if its under wrty & service according to schedule at SC, engine damage due to t.belt snap shld b covered.
shld also look at which SC u send. i faced claims problem at smaller authorised SC but when send to big main SC i got it claimed w/o problem..

CONCLUSION = test drive both the cars.. decide after tht..
test = used altis vs used persona, so u can judge the car which is already done some km's on the road..