Question

Do we need to enter in to a black hole for time travel or just ORBITING AROUND IT will be enough????

Answer 1

Theoretically, its possible from both ways. But. I've a strong doubt now that you've watched interstellar, then mind you there Cooper never got into the black hole for time dilation!
Anyway, back to the topic. Time dilation is still like a dream & fantasy for us, we don't have any clue of the technology either. I wanted to elaborate it a bit but then I thought that you've asked a simple question...So, in both ways. & it has been estimated that if you re just orbiting around the black hole, the time dilation of your space ship will be twice as fast as that if earth.
Cheers!

Answer 2

here goes your answer

It is proven that near black holes or inside black hole space and time is distorted so in both the cases we can travel time. but if we go inside the black hole what Will happen no one knows about it. you may die even. but There are no known black holes anywhere near us . So you will still need to travel near light speed or at it if you want to get near to a black hole within a human lifetime otherwise your lifespan will be completed before reaching a black hole so you will have travel at the ‘near light speed’ “ to access the ‘near black hole’ “time travel”.and yes in both the cases you can travel time as it has been proved theoretically.