i shared mobile number with merchant and realized that i dont have sufficient balance to complete the payment what should i do

You can add money in Paytm and then share the OTP to complete the payment.

• You can add money to your Paytm Wallet by selecting the Add Money tab on homepage
• Enter the amount you want to add and tap on ‘Add Money’
• You can choose to add money via Credit/Debit card, Net Banking, IMPS or ATM card
• You will be redirected to a secure payment page where you need to provide payment details