Zebpay has made it very clear with their statement on June 21,2018 regarding the RESERVE BANK OF INDIA CIRCULAR: drr. no.bp.bc.104 /08.13.102/2017 dated April 6 , 2018
That if by any means ZEBPAY'S BANK accounts are disrupted they will not be able to payout any rupees, however there is no statement regarding transfer of cryptocurrrencies .
According to them the user can opt to withdraw their rupees as long as their accounts are working and they will process it.
SOURCE - ZEBPAY