The Nifty Oil & Gas Index consists of up to 15 of the largest and most liquid companies in the oil, gas, and petroleum sector listed on the National Stock Exchange (NSE). The index is calculated using the free float market capitalization method and is rebalanced semi-annually. Current Constituents (as of June 2025) Below are the main constituents of the Nifty Oil & Gas Index, based on recent listings and weightages: Company Name Symbol (NSE) Notable Details/Weightage* Reliance Industries Ltd. RELIANCE Largest weight (~33.8%) Oil & Natural Gas Corp. Ltd. ONGC ~14.5% weight Bharat Petroleum Corp. Ltd. BPCL ~9.6% weight Indian Oil Corp. Ltd. IOC ~8.3% weight GAIL (India) Ltd. GAIL ~8.0% weight Hindustan Petroleum Corp. Ltd. HINDPETRO ~6.2% weight Oil India Ltd. OIL ~3.6% weight Petronet LNG Ltd. PETRONET ~3.6% weight Adani Total Gas Ltd. ATGL ~3.0% weight Indraprastha Gas Ltd. IGL ~2.3% weight Gujarat Gas Ltd. GUJGASLTD Included in index Aegis Logistics Ltd. AEGISLOG Included in index Castrol India Ltd. CASTROLIND Included in index Gujarat State Petronet Ltd. GSPL Included in index Mahanagar Gas Ltd. MGL Included in index