Do I need to have balance in my bank account to get installment payment done?

Yes for Grab Pay Later installment with debit card because Grab will deduct first payment from your bank account immediately upon purchase. If you do not have sufficient balance, the first payment will not be successful. For deferred payment also, you need to transfer 1st month payment to us upon purchase. For credit card, it may not be necessary to have sufficient balance but your credit limit must cover total purchase amount.