hi gaurav. I agree a lot with dreamz.
Your accomodation depends a lot on where HMC plans on making you work. If it is in Wakra, accept the Barwa village as it is closer, I however do not recommend accepting the housing allowance for 6K as it is peanuts. Accept the accommodation, but after careful negotiation. All the best.

oh and btw, your inital accommodation will be in the HMC guesthouse in Bin Omran or in the Medical city