HI Sukhwinder,
I think, If your funtional users made modfication in tables/objects then SPDD window will be prompt during ADJUSTCHK_PRE.
If you made modification and SPDD window did not prompt then you can adjust to modified object after upgrade and you can do it with the help of funiontal and abaper.
I am also upgradating EHP 6 and I faced some modification during this phase because funtional users and ABAPER had made some modification in tables/objects. so, I login on shadow system and made the modification.
Regards,