No, as per my k knowledge, there is no office of Indian Oil Corporation Ltd in Warangal. Its offices are at:

TELANGANA & ANDHRA PRADESH
Indian Oil Corporation Ltd, No. 3-6-436 to 438, II & IIIrd Floor, Naspur House, Himayat Nagar, Hyderabad - 500029
040-27617332 040-27632805

BIHAR
Indian Oil Corporation Ltd., Loknayak Bhavan, Dak Bunglow Chowk, Patna - 800001
0612-2234754 0612-2211629

DELHI
Indian Oil Corporation Ltd.(MD), 2nd floor World Trade Center, Babar Road, New Delhi - 110001
011-23412475 011-23413022

GUJARAT
IndianOil Bhawan, 205, Near Sola flyover, S.G. Highway, Ahmedabad – 380060
079-26562621

KARNATAKA
Indian Oil Corporation Ltd. IndianOil Bhavan, No. 29, P. Kalinga Rao Road (Mission Road), Bangalore - 560027 080-22160900/10
080-22278996

KERALA
Indian Oil Corporation Ltd., Panampilli Nagar, Panampilli Avenue, Cochin – 682036
0484-2319898

MADHYA PRADESH
Indian Oil Corporation Ltd., Indian Oil Bhavan, 16 Arera Hills, Jail Road, Bhopal - 462011
0755-2557157

MAHARASHTRA
Indian Oil Corporation Ltd., IndianOil Bhawan, Plot No.33, G Block, Bandra Kurla Complex, Bandra (E) Mumbai - 400051
022-26722701

NORTH EAST INTEGRATED
Indian Oil Corporation Ltd., East Point Tower, Bamuni Maidan, Guwahati – 781021
0361-2550604

ORISSA
Indian Oil Corporation Ltd., A/2, Chandrashekarpur Bhubaneswar – 751024
0674-2745830 0674-2745832

PUNJAB, HIMACHAL, J&K
Indian Oil Corporation Limited, IndianOil Bhawan, Plot No. 3A, Sector 19 A, Madhya Marg, Chandigarh - 160019
0172-2549166

RAJASTHAN
Indian Oil Corporation Ltd.(M.D.), IndianOil Bhawan, Ashok Chowk, Nr. Radha Swami Satsang Bhawan, Adarsh Nagar, Jaipur - 302004
0141-2601234, 0141-2601318

TAMIL NADU I
ndian Oil Corporation Ltd., Indian Oil Bhavan, 139, Nungambakkam High Road, Chennai - 600034
044-28330121

UTTAR PRADESH-I
Indian Oil Corporation Ltd., Indian Oil Bhawan, TC-39 V, Vibhuti Khand, Gomti Nagar, Lucknow - 226010
0522-2305707 0522-2305711

UTTAR PRADESH-II
Indian Oil Corporation Ltd., E - 8, Sector - 1, Noida - 201301
0120-2538405

WEST BENGAL
Indian Oil Bhavan, 2, Gariahat Road (South), Dhakuria, Kolkata - 700068 033-24145564