Single PNR but different boarding point

I have booked ticket for two people in single PNR. Now thing is that my partner will be boarding first at 3 am and me from different station 6hrs later.

I have checked with TT in different train, he said boarding point can't be changed for single person under one PNR needs to be changed for both. Is there any way we can make this work, we are planning to tell TT that second person i.e. me is in washroom, since it's overnight train I don't think he'll come back to check.

Please suggest if there's any other way we can make this work.

P.s. I got urgent work at last moment that caused this, originally we both had plan to board from original station.