Drain it completely and spread it in a clean cloth and dry it under fan for 3 hours.
Now take the rice in a blender and powder it finely. Use a fine sieve and sift the mix.
After you sieve, if you get lots of coarse rice mix, powder it again and sieve it.
Now heat a thick bottom kadai, add the powdered rice and roast it for 5 mins or so on a medium heat till the wetness dries off.
Spread it on a clean paper to cool down. Store it in a air tight container.
Notes
1)You can store this powder in a air tight container for 3 to 4 months.2) Grinding this in mixie is a pain, you have to keep on grinding it till you get fine powder. It will take lots of time. You can make this in bulk and give this to mill, this way it will be more finer and less fuss.3)If you grind the rice at home, you have to do it in batches. As you sieve the mix, you will get coarse rava like mix, add it to the next batch and keep grinding till you get fine flour.