Do we need to give FIR if we loose just TCS ID card? What's exact process?

No need to they will just block the card go to ultimatix apply for new card

First of all report the loss of the card to the supervisor and HR. You can ask HR if you need to file an FIR and your supervisor can grant you temporary access to TCS premises. You will have to raise a new request for the card and pay a penalty for the lost card.