First rinse the raw rice twice, and soak it in water for 1 hour. Drain water completely and then spread the raw rice in a soft towel and allow it to dry say for 30-45 mins. It will be slightly moist only. Then transfer this to a mixer. Grind it to a fine powder in a mixie in batches.Then sieve it. If you find small balls break and sieve it. Sieve until you get rava like mixture.Add it to the next flour batch and grind it again. Dry roast the sieved flour until you see steam coming out of the flour.Cool down by spreading in a newspaper.