Question

he is ill since three months(correction)​

Answer 1

Hlo mate

Here's your correct sentence

He is ill till three months.

Hope it's helps you ✌✌✌✌♥️

Answer 2

he is ill from 2 months.

till can't be used here bcoz,it denotes when something will happen.

so don't be confuse.

hope it helps you dude