It isn't easy to consistently makeR$50 orR$100 a day playing poker. Because in poker some days you will win and some days you will lose. However, if you want to makeR$50 orR$100 a day on average playing poker, then you should play low stakes cash games.
Regarding minimum buy-ins, most poker rooms have minimum buy-ins of somewhere between 20 and 40 big blinds. Regarding maximum buy-ins, the majority of poker rooms (especially online) have a cap of 100 big blinds. In deepstack games, these maximum limits can increase to 250 big blinds or even more!