How are securities tax under the Income Tax Act(India)?

Under the Income Tax regulations, how are capital gains from securities taxed. What is the process of filing tax for these transactions with the Income Taz department
Short Term Capital Gains (STCG) from sale of shares through recognized stock exchange or units of equity MFs with STT paid are taxed @ 15% Short Term Capital Loss (STCL) from sale of shares through recognized stock exchange or units of equity MFs with STT paid can be adjusted against any Short Term Capital Gains (STCG) or Long Term Capital Gains (LTCG). Long Term Capital Gains (LTCG) from sale of shares through recognized stock exchange or units of equity MFs with STT paid are tax free. Long Term Capital Loss (LTCL) from sale of shares through recognized stock exchange or units of equity MFs with STT paid can be adjusted against Long Term Capital Gains (LTCG) from sale of shares through recognized stock exchange or units of equity MFs with STT paid. In your ITR you have to declare Capital Gains under Schedule CG. HMT

Is All winnings from contests are subject to tax deduction at source under section 194B of Income Tax Act-1961?

My Question is: what are responsibiltes of Organizer/Host of such event. or is it all responsibilty of winner contestant to pay tax . What if contestant is student above 18 .