Expenses and living in JORDAN

Welcome Gaurav...
Regarding life costs, I think the offer is not that strong, specially if you have to pay for the rent, and most if you will be living in Amman as I think.
a small flat monthly rent would go from 200 - 350 JD. depending on the area.

food is as expensive in other countries. But Indian ingredients here would cost much and I don't think you would find all you want.

clothes, entertainment...etc that depends much on you, and what you look for.

Normally, if you have family here, a house, and you share expensive with family members, then 600 JD would be ok... but you can not save much.

Temperature is ok... for people coming from Karala
if you stay in amman then the maximum would get as high as 38 sometimes or maybe 40.
but since I have been living out for the last few years, they tell me if has changed.

You'll survive heat, dont worry... I think you might wanna think about cold weather more when it is winter.
That of course depends on what temperatures you have there in your area.

Best Luck