Thanks @Fayaz02
I havn't rome much around Derawar area because of hot day. But I think there is no accomodation available there. I saw a pin drop of TDCP resort on google map at Derawar but I guess they only provide camping and food while any event days.
No public transport available and its highly recommend to hire a car from Bahawalpur. I am not sure how much they charge but Derawar is around 200km round trip from Bahawalpur. So they might charge you between 7k to 10k.
Also if you travel to Derawar, have food with you as there is no restaurant to serve you except TDCP (if they are available). And in the summer season, keep plenty of water to stay hydrated.