@Jay Vagheshwari Maa ,
If you are opening minor ac in HDFC then visit ur local branch, update the minor PAN number. Some bank employee doesnt know about that so they say no at the first time. So, simply tell them, Bank has this facilities, ur friend or relative has such thing in so and Town / city etc. So, you contact to the higher authority.
Or, best option b4 opening the a/c go and ask the bank that u will open the minor account if they update the minor PAN later because u will apply for IPO. In that case, once they commit they cant refuse later or b4 opening the ac they will get the info from higher incase if they dont know. Coz its a matter 10,000 + 5,000 =15,000 minimum balance and 1 new account for the bank... :) :).
Next, once opened,
1)if you want to apply from net banking, then put money in the minor account always. And during application time u would find 2 accounts (gurdian + minor), select minor account.
If minor PAN is updated it will directly show in the IPO details page, there you have to write minor's DEMAT number, for every IPO application and thats all.
2) if u apply from PhonePe then you have to create PhonePe id linked with the gurdian account as atm card that u will receive is linked with the gurdian account by default. In that case keep ipo application amount in the gurdian account only. And from minor's demat ac u select that phonepe id and pay. This is also valid.
I hope its clear to you now.