Is OD (Original degree) from JNTUK necessary to join a job in an MNC? Will they ask for it on the day of joining?

No, it is not necessary to provide OD at the time of joining a job in an MNC. If you have OD at the time of joining, you can use it. Otherwise, the mark memorandum with your marks throughout the 1-8 semesters will be sufficient. You can also get a course completing certificate from your college. You can talk to HR about it, they will cooperate.