@Arora ji, like
@MayankG said, it may take some time. Just wait. If hold doesn't get removed after 24 hrs, you may write to LinkinTime. Refer to their email statement of allotment status when received (usually within 24 hrs). Their phone number and email (different for each ipo) both are given at its bottom to resolve such issues.
Though sometimes it takes more than 48 hrs after allotment is out. I needed that email link once only, but hold got removed before LinkinTime's reply, around the 3rd day.