As per law, tax deduction at source (TDS) may be applicable on your winnings. TDS is currently applicable at the rate of 30% on winning above ₹10,000 and the rate of TDS and/or the exemption limit are subject to changes from time to time as required by law. For example: Suppose you participate in a contest with ₹100/- entry fee and win ₹12,000/- in that contest.
Since your net winning in that contest is ₹11,900/- (₹12,000/- minus ₹100/-) which is greater than ₹10,000/-, a TDS of 30% will be applicable of the net winning amount (₹11,900/-) and will be deducted from the winning amount (₹12,000/-). ₹3,570/- (₹11,900 x 30%) will be deducted from your winning amount and your account will be credited with ₹8,430/- (₹12,000/- minus ₹3,570/-).