And it is wise to complete kyc there before starting gambling.
Wise? More like unwise. You people are missing the point. Submitting KYC to a reputed gambling site before gambling away does not guarantee that they won't request KYC again and again repeatedly in the future.
Also, reputed sites sometimes turn dark and screw their users by stealing their money, KYC details etc. For example, we have Betnomi etc that screwed their customers out of the blue. Think!
It still happens during the withdrawals requests..