Take ragi in a vessel and wash it by rubbing well with your hands. It has lots of mud so repeat the process 2 to 3 times unless it is clean and get rid of all dirt.
Then soak the ragi in clean water for 12 hours. Keep it covered (with provision to some air to enter) while soaking. After 12 hours, open. The color of the ragi will be changed after soaking.
Then drain the water completely. Transfer the drained ragi to a clean white cloth or cheesecloth for sprouting. Place the cheesecloth with ragi in a colander.
Tie it up with all four corners and keep it undisturbed for another 12 hours for sprouting. After 12 hours, open the cloth carefully. You could see the tiny sprouts in ragi. Transfer the sprouted ragi to a plate and sun dry it for 12 hours.
After sun drying the ragi, dry roast the ragi in a pan in low flame for 5 minutes or until it's toasted. Remove from the pan and cool it down.
Take the roasted ragi to a dry mixer jar and blend it to a smooth powder. Sieve the powder well. Cool it down and store in an airtight container.