now the only way out for you is to get a fresh ticket from ADI to ST, and board your coach from ST, as you cannot board from ADI(even if your ticket is from ADI) it will be treated as ticket From ST, as you have changed your boarding point. Boarding can be changed once only, hence you cannot re-change your boarding point. If you board form ADI, you will be treated as ticketless traveller and will be penalised