I need help here. In the video itself, I can't see any gap. In Premiere Pro, no gaps also. But when I put the video to After effects, gaps suddenly start appearing in the timeline. I try to delete them, but afterwards, gaps suddenly starts reappearing again. I really need help here.
We can't know. Your description is at best vague, but honestly more to the point of being useless. You need to provide system information, details about your footage, screenshots of your sequence/ timeline in both programs and so on.
What's a gap? Check your frame rates.