No problem I will get the office address of Oil and Natural Gas Corporation, located in Silchar so that you can remember the route.

Here is the address
ONGC Ltd.,
CacharForward Base,A&AABasin,Srikona, Silchar - 7880826

Phone:-
(03842)-285502

Apart from Silchar I have some more offices details
Agartala
ONGC Ltd.,
Tripura Asset
BADHARGHAT COMPLEX, AGARTALA - 799014. TRIPURA

Ahmedabad
ONGC Ltd.,
Ahmedabad Asset
Avani Bhavan, Chandkheda, Ahmedabad-380005

Ankleshwar
ONGC Ltd., Ankleshwar
Asset
Ankleshwar Asset, Ankleshwar-393010, Distt: Bharuch, Gujarat

Bokaro
ONGC Ltd.,
CBM Development Project
First Floor HSCL Building, Bokaro Steel City, Bokaro-827001

Cambay
ONGC Ltd.,
Cambay Sub Asset
ONGC, Post Kansari, Khambhat - 388630, Distt. Anand, Gujarat

Chennai
ONGC Ltd.,
CMDA Tower I, No. 1 Gandhi Irwin Road, Egmore, Chennai-600008

Dehradun
ONGC Ltd.,
Green Building, 1st floor, Tel Bhavan,Dehradun 248003.

Delhi
ONGC Ltd.,
10th Floor, Kailash Building, 26, Kasturba Gandhi Marg, NewDelhi - 110001

Goa
ONGC Ltd.,
P.O. via Velim, Betul, South Goa 403723
Hazira ONGC Ltd.,
Hazira Plant, PO ONGC Nagar, Surat-394518

Jodhpur
ONGC Ltd.,
Rajasthan Forward Base
KDM Complex, Mandore Road, Jodhpur-342 026

Jorhat
ONGC Ltd.,
Assam & Assam Arakan Basin
Luit Bhawan, ONGC, Cinnamara Complex, P O : Cinnamara, Dist: Jorhat , Assam, PIN: 785704

Karaikal
ONGC Ltd.,
Cauvery Asset
Neravy Office Complex, Neravy (PO), Karaikal - 609 604, Pondicherry U/T

Kolkata
ONGC Ltd.,
41 Jawaharlal Nehru Road, 2nd floor, Kolkata 700071

Mehsana
ONGC Ltd.,
Mehsana Asset
KDM Bhavan, ONGC, Mehsana Asset, Palavasana, Mehsana-384003

Mumbai
ONGCLtd.,
Vasundhara Bhavan, 1st floor, RooM No. 114,Bandra(E), Mumbai-400017

Nazira
ONGC Ltd.,
Assam Asset
Nazira, District-Sivasagar, Pin-785685, Assam

Rajahmundry
ONGC Ltd.,
Rajahmundry Asset
ONGC, Godavari Bhavan, Base Complex, Rajahmundry-533 106,East Godavari District (A.P.)

Uran
ONGC Ltd.,
MR, Uran Plant, Uran 400702 Maharashtra

Vadodara
ONGC Ltd.,
Western Onshore Basin
ONGC, Makarpura Road, Vadodara – 390009

Address:-
Oil and Natural Gas Corporation
Jeevan Bharti, Tower –II, 124 Indira Chowk
New Delhi – 110001

Phone:-
2330100