Everyone is a gangster (Rajdhani, Shatabdi, Tejas) until the real Gangsta (Vande Bharat) walks in 😂 - Mushfique Khalid

yes, it is compulsory for tatkal tickets . with out id proof you will treated as ticket less passenger and will also be fined heavily.any of the id proof from the following is required:
1]passport
2]2-3 wheeler license
3]voter id card
4]pancard...
more...

,5]photo identity card issued by Central/State Government, student identity card with photograph issued by recognised school/college, nationalised bank passbook with photograph or credit cards issued by banks with laminated photographs.
but no proof is required to be produced at the reservation counter while booking the tatkal ticket