Hello,
Pratyushv9. If the local test center is closed, then the Online Exam seems like a decent option, provided you have a reliable connection. (Some members have reported extreme lags or crashes.) If GMAC™ says that a score is valid, then it is valid, and an Online Exam score cannot be held against you. I would not worry about scores potentially getting revoked. That has to be such a rare occurrence that it barely warrants discussion. I assume you are not planning on cheating? If that is so, then why get yourself worked up over nothing? Just sit the exam, put in the best performance you can, and, hopefully, get cracking on the next step in the application process.
There is no consensus as to which exam is easier, harder, more or less convenient—yes, some people find the online environment less convenient, since their own living space might not work for some reason and they may be forced to go someplace else. It sounds as though you like to plan ahead. Just think the practical matters through (connection, environment, travel to the nearest open testing center, and so on), and make an informed decision. If you worry too much about taking the test, you will be more likely to perform at a level you may be unhappy with.
Good luck.
- Andrew