I have mistakenly filled incorrect DP Id in my application. The IPO is closed now. What should I do?

The DP id is an important information in your IPO application and once the bidding is closed, there's very little you can do. You can correct the information in case the bidding process is on. Your application may be rejected due to mismatch in name and DP id. However, get in touch with the registrar of the IPO and explain him the situation.