Thanks I wanted to use it for free spectrum which are available in India and I know there are have attached the licenced free band in IndiaThere are lots of DIY radio schematics available, for many different frequencies and power levels.
However, unless you have an appropriate level Amateur Radio licence in whatever country you live in, it's generally illegal to use any home-built radio equipment.
(Or any with sufficient power top work over more than a couple of metres, anyway).
Mass produced "consumer grade" pre-approved ones are available very cheaply in many countries.