What will happen if the buy order for NFO is given after the offer period?

If a client places the order for an NFO after the expiry of the offer period, then the order will be rejected. Hence, make sure to put an NFO order during the offer period and if your mutual fund order is still being rejected, then you can contact support team of BSE STAR MF via Phone:  022-45720450 or 022-45720650 on business days from 8 AM to 7 PM or Email: bsehelp@bseindia.