Why can't I see the shares I acquired from ESOP under holdings on Tiqs?

There will be a lock-in period for shares acquired through an ESOP (Employee Stock Option Plan), which prevents you from selling the shares before it is over. The shares aren't offered on Tiqs because of this.

However, the shares will be in your demat account. You may check and reconcile them by looking at the demat holding statement (Statement of Transaction), which will make them available.