Whisk the curd in a bowl and add sooji into it. Mix them well followed by adding salt to it. Whisk the mixture once again and leave the mixture for 20 minutes. Put baking soda into the mixture after 20 minutes and mix it well. Make sure that the mixture should not neither too thick nor too thin.
Take a cooker and pour 2 small glass of water in it. Let the water warm up. Meanwhile, take the idli stand and grease it with little oil. Pour the mixture with the spoon in the sections of the stand. You can make 12-15 idli at the same time depending on the size of the idli stand. Keep the idli stand in the cooker and cover it with the lid without the whistle. The idli gets cooked in 8-10 minutes. Open the lid and check whether the idli is cooked properly from inside with the help of a fork. If the fork comes out clean then the idli is ready. Take out the idli stand from the cooker and let it cool down. Take out each idli from the idli stand with the help of a spoon and put them on a plate.
Rava Idli is ready. Serve it with sambar, coconut chutney, channa dal chutney or peanut chutney.