Yes you M tech and Public sector undertaking examination are good options after passing B tech electronics and communication engineering.

It is completely depends on your interest and ability to choose between M tech and Public sector undertaking examination for better future.

M tech course will provides you specialized knowledge for your engineering stream. You will get many better career options after passing M tech course. But if you want to get a better job than you have to apply for PSU exams..

Top PSU companies :
REC Power Distribution Company
Brahmaputra Cracker and Polymer Limited
Electronics Corporation of India
Bharat Heavy Electricals
Hindustan Vegetable Oils Corporation Limited
Bokaro Kodarma Maithon Transmission Company
MMTC
ITI
Bharat Pumps & Compressors
Braithwaite & Company
Hindustan Antibiotics
India Trade Promotion Organisation
North Eastern Handicrafts & Handloom Development Corporation
Bharat Petro Resources JPDA
HMT Chinar Watches Limited
Ennore Port
Fertilizer Corporation of India Limited
Instrumentation Digital Control
Bharatiya Nabhikiya Vidyut Nigam
Mahanadi Coalfields
Kumarakruppa Frontier Hotels
Nagaland Pulp & Paper Company
MECON Limited
Sakhigopal Integrated Power Company
National Textile Corporation
NLC Tamil Nadu Power
Hindustan Photo Films Manufacturing Company
New India Assurance Company
HMT Machine Tools Limited
Security Printing and Minting Corporation of India Limited
Scooters India
National Scheduled Castes Finance and Development Corporation
Goa Shipyard
Millennium Telecom
Rural Electrification Corporation
Bhartiya Rail Bijlee Corporation
Hindustan Insecticides
Hindustan Fertilizer Corporation Limited
Hindustan Steelworks Construction Limited
Bihar Drugs & Organic Chemicals
Oriental Insurance Company
Educational Consultants India Limited
Mumbai Railway Vikas Corporation
Indian Renewable Energy Development Agency
Rites
Karnataka Antibiotics & Pharmaceuticals
HMT Watches Limited
Hindustan Organic Chemicals Limited
Burn Standard Company
Numaligarh Refinary
Coal India Limited
Ircon International
Dredging Corporation of India
Fresh & Healthy Enterprises
East North Interconnection Company
British India Corporation
Fertilisers and Chemicals Travancore
Neyveli Lignite Corporation
Central Inland Water Transport Corporation
NMDC
Richardson & Cruddas
HMT
Kanti Bijlee Utpadan Nigam
HMT (International) Limited
National Projects Construction Corporation
Mangalore Refinary & Petrochemicals
Hotel Corporation of India
Hindustan Cables Limited
State Trading Corporation of India
PEC
Coastal Maharashtra Mega Power
Nationalised Banks
Maharashtra Elektrosmelt
Delhi Metro Rail Corporation Limited
Engineers India
Coastal Karnataka Power
SJVN
FCI Aravali Gypsum & Minerals India Limited
National Safai Karamcharis Finance and Development Corporation
North Eastern Regional Agricultural Marketing Corporation
Central Railside Warehousing Company
Rajasthan Electronics and Instruments
Cochin Shipyard
Heavy Engineering Corporation
Oil & Natural Gas Corporation
Mishra Dhatu Nigam
Oil India
Steel Authority of India
Nuclear Power Corporation of India
Mineral Exploration Corporation
Hindustan Newsprint
Indian Oil Technologies
National Film Development Corporation of India
Engineering Projects (India) Limited
Bharat Electronics
North Eastern Electric Power Corporation
Hindustan Fluorocarbons Limited
GAIL (India)
Punjab Ashok Hotel Company
Broadcast Engineering Consultants India
NTPC Vidyut Vyapar Nigam
KIOCL
National Backward Classes Finance and Development Corporation
Rashtriya Chemicals & Fertilizers
Shipping Corporation of India
Indian Railway Finance Corporation
India Infrastructure Finance Company
National Handicapped Finance and Development Corporation
Indian Drugs & Pharmaceuticals
National Aviation Company of India
Ferro Scrap Nigam Limited
Biecco Lawrie
Nepa
Konkan Railway Corporation
Northern Coalfields
Gail Gas
Ghogarpalli Integrated Power Company Limited
Certification Engineers International
Damodar Valley Corporation
Chennai Petroleum Corporation
Narmada Hydroelectric Development Corporation
NTPC Hydro
Export Credit Guarantee Corporationof India
National Insurance Company
IDPL (Tamil Nadu) Limited
Orissa Integrated Power
Indian Railway Catering and Tourism Corporation
Hindustan Prefab Limited
I A L Airport Services
Housing and Urban Development Corporation
Indian Rare Earths Limited
Bharat Petroleum Corporation
Creda HPCL Biofuel
National Aluminium Company
Rashtriya Ispat Nigam
Jute Corporation of India
ONGC Videsh
Cement Corporation of India
Hooghly Printing Company
National Jute Manufactures Corporation
Indian Medicines & Pharmaceutical Corporation
PFC Consulting
Hindustan Petroleum Corporation
Ranchi Ashok Bihar Hotel Corporation
Madhya Pradesh Ashok Hotel Corporation
Brahmaputra Valley Fertilizer Corporation
HSCC
Cotton Corporation of India
Sponge Iron India
Bridge and Roof Company
Central Mine Planning and Design Institute
Handicrafts and Handlooms Export Corporation of India
Hindustan Salts Limited (Sambhar salt)
HMT Bearings Limited
NTPC Electric Supply Company
Madras Fertilizers Limited
Hindustan Aeronautics
Dedicated Freight Corridor Corporation of India
J & K Mineral Development Corporation
Bharat Petro Resources
National Fertilizers
Sethusamudram Corporation
Hindustan Copper Limited
Manganese Ore India
Central Warehousing Corporation
Hindustan Shipyard
Rail Vikas Nigam
HLL Lifecare
Eastern Coalfields
Karnataka Trade Promotion Organisation
Instrumentation
Central Electronics Limited
National Buildings Construction Corporation
National Minorities Development and Finance Corporation
REC Transmission Project Company
Railtel Corporation India
National Handloom Development Corporation
Bharat Immunologicals and Biologicals Corporation
Donyi Polo Ashok Hotel
India Tourism Development Corporation
Orissa Drugs & Chemicals
Jagdishpur Paper Mills
Central Coalfields Limited
Indian Vaccine Corporation
MSTC
Indian Oil Corporation
Pondicherry Ashok Hotel Corporation
Central Cottage Industries Emporium
National Research Development Corporation
Pawan Hans Helicopters
Mazagon Dock
Instrumentation Control Valves
Hooghly Dock and Port Engineers Limited
Garden Reach Shipbuilders & Engineers
STCL
Power Finance Corporation
NTPC
Food Corporation of India
Rajasthan Drugs & Pharmaceuticals
National Scheduled Tribes Finance and Development Corporation
National Seeds Corporation
North Karanpura Transmission Company
Bharat Refractories
Bharat Heavy Plate & Vessels
National Small Industries Corporation
State Farms Corporation of India
Container Corporation of India
Projects & Development India
Hindustan Paper Corporation
Bharat Wagon & Engg. Company
South Eastern Coalfields
Il Power Electronics Limited
Power Grid Corporation of India
Bharat Sanchar Nigam
Birds Jute & Export
National Informatics Centre Services Incorporated
Mahanagar Telephone Nigam
Coastal Tamil Nadu Power