I believe you will be travelling by Air.
India's national carrier, Air India's document page states
- Valid travel document for Indian citizens are
- Valid Passport,
- PAN card issued by the Income Tax department,
- Election Photo Identification Card,
- Valid Driving License,
- Photo identity card issued by the employer, being government and
reputed private sector organizations,
- Photo Credit Card,
- Children should carry their school identification cards or any other
photo
- identification proof,
- Valid birth certificates of infants,
- For travel under Concessionary fare types valid relevant IDs.
For Foreign Nationals, the only valid photo ID for travel is Passport.
So you need to have your passport for your travel.