How is UPM account in TCS? Are they flexible about office hours?

It all depends on the project you are assigned to in that particular account.
In my experience the account can be generally good but the project can be a nightmare. So you would need to know the Project to understand the above mentioned questions.
Right now my PoV most projects are a mess. Most of them is in chaos and along with that policy pressure is at an all time high. So you may need to be in office for specified standard policy hours.