As you asking here I am telling short info of both companies Bharat Heavy Electricals Limited (BHEL) and Oil and Natural Gas Corporation Limited (ONGC),

Bharat Heavy Electricals Limited (BHEL) owned by the Government of India, is an engineering and manufacturing company based in New Delhi, India.

Company profile :
Type
Public
Industry Electrical equipments
Founded 1964
Founder Government of India
Headquarters New Delhi, India
Area served
Worldwide
Key people
Atul Sobti, (Chairman & MD)
Products Gas and Steam Turbines, Boilers, Electric Motors, Generators, Heat Exchangers, Pumps, Switchgears, Sensors, Automation and Control Systems, Power electronics, Transmission systems etc.
Revenue 26,350.60 crore (US$3.9 billion) (2016)
Net income
-897.39 crore (US$−130 million) (Loss)(2016)
Total assets 75,242.57 crore (US$11 billion)
Total equity 33,156.87 crore (US$4.9 billion)
Number of employees
42,192(March 2016)

Oil and Natural Gas Corporation Limited (ONGC) is an Indian multinational oil and gas company headquartered in Dehradun, Uttarakhand, India. It is a Public Sector Undertaking (PSU) of the Government of India, under the administrative control of the Ministry of Petroleum and Natural Gas

Company profile:
Type
Public Sector Undertaking
Traded as NSE: ONGC
BSE: 500312
BSE SENSEX Constituent
CNX Nifty Constituent
Industry Oil and Gas
Founded 14 August 1956
Headquarters Tel Bhavan, Dehradun, Uttarakhand, India
Key people
Dinesh Kumar Sarraf
(Chairman & MD)
Products Petroleum, natural gas, and other petrochemicals
Revenue 139,364.35 crore (US$21 billion) (2016)
Profit 14,300.93 crore (US$2.1 billion) (2016)
Total equity 4,277.76 crore (US$640 million)
Owner Government of India
Number of employees
33,560 (1st Aug 2015)
Divisions MRPL
ONGC Videsh Ltd.