Guys I have 4 days to accept the offer of 9 lpa from tcs having 5 yoe, can I ask them more? Or I can say yes to online offer then ask more?

I think You can ask for more the worst they could say is they can not provide that much. I am not much experienced but I believe it should work.

It's better to reject

Please don't go with 9LPA with the year of experience you hold, keeping in mind your salary won't increase for another 3years you have to survive on this only. Moreover 9LPA in Bangalore you can't survive my teammate with family was not saving any penny with 15LPA So think wisely, now since you are an immediate joiner keep looking for job opportunities.