If he is having tummy issues, do not intro solids... his gut is not mature enough at this age regardless so it will just cause worse tummy pain and waking during the night/naps. Wait until he is 6 months.
Yeah, I wouldn't use water or formula in India either..
Check with the airline about formula supplies - there are different rules with some airlines in terms of things you need for baby.
I can't say that Gerber is a better formula since all formulas have to meet the same standards, but I will say my DD did very well on it
