Documents verification will be done after completing the website/app verification as sequential step. Usually, 2 step verification is required to upgrade your account.
1. Website/App verification
2. Documents verification
Please ensure that your website/app is live and working with all the mandatory information available. Refer to this link for more details - https://business.paytm.com/blog/ecommerce-payment-gateway-guidelines/
Once your website gets verified, and documents are approved. It will take a few hours to upgrade your account.