New guy to Oman

Hi,

I received an offer from a consulting company for software Test lead position having 7+ years. I am a B.Sc graduate and did PGDBA part time. The below is my offer

"Do you accept the offered salary 850 PM (Remuneration is
all inclusive, Salary OMR 450 + Housing allowance (OMR 300)
& Conveyance Allowance (OMR 100) is part of the salary)"

1. I wanted to know whether this enough for a couple living middle-class life. I expect to save 70,000 INR per month.
2. I also wanted to know the cost for health plans.
3. As of now the contract is for an year and subjected to change. Any origin docs i should submit to them for being a contractual position?
4. Can they legally sue me if i break the contract
5. If I can negotiate further, what and all i can request them?

Note - i have to bare all the costs and not sure about the city where I will be placed.

Thanks,
Vadhav