I have both comedk and amrita University, exam in same day and comedk examination centre is Faraway from my native ,so Suggest me which exam is better to attend ?

Well, asking my opinion I'll suggest you to go with COMEDK, because you'll be having number of options while selecting college but that doesn't mean amrita is not a good University, if you're willing to take admission in amrita go for it but you're willing to go for RVCE, BMS or Any other college then go for COMEDK.
selection of the exam is based upon your priority of college.

Hope you make the best decision for yourself

All the best.