Unfortunately I have to say that nothing is safe and guaranteed here in the world of crypto. There is no fixed ROI in reality here. If there is, that would be mostly from the scammers and ponzi opportunities.

You can do staking if you want and achieve an APY percentage. However, it would be in the form of altcoins where the prices are not stable and guaranteed despite you’re gonna achieve that number of coins or tokens after the locking period is over.

And as for the centralized exchanges like Binance which has flexible savings plan, I do not think I can count on them to save and stake my funds as we do not have the full custody of our assets there.