Hello dear student, 

Greetings! 

It depends on the university,  but most of the Universities don't deduct your percentage for gap years. If we talk about the most reputed university,  DU then   DU has also decided to treat gap year students on a par with fresh pass-outs and there will be no deduction of percentage under the same clause.

 The admission procedure is same for gap year candidates as like freshers. No any deduction in aggregate or extra documents for gap year students

Thankyou