Do i need to pay tax for profit earned or?

i know we pay STT.Tax etc for individual trades initiated.but after one year say if i have profit earned Rs.500000 do i need to file IT returns?for the profit earned as a individual trader?

Yes, taxes are applicable. Here is all that you need to know about taxation - http://zerodha.com/z-connect/traders-zone/taxation-for-traders/taxation-for-traders-introduction