if uncooked shabudana( Tapioca) is soaked for 2 day i put this mixture in fridge, is it still safe to eat (after it's cooked)?

So it seems you soaked it in outside room temperature (how hot was the weather?) and then put it in fridge after two days? Does the soaked mixture have any 'odd' smell coming from it? That is one way to tell if it is not good. Cooking might kill any yeast or bacteria, but if other toxins have been prepared by those germs then those might still be present. If you can afford to throw it, please do. By that, I mean, compost it or something if you can.