Tilyar Lake Restaurant
At the doorstep of Rohtak
on Rohtak-Delhi Highway
The Bar serves Hard drinks but donot have much of the options but it have nice ambiance.
Myna Restaurant
Near Ashoka Chowk
Apart from drinking, you can also try the food here which comes on the reasonable prices.
AnnaPurna
near Ashoka talkies
Very good all time hangout. Nice cuisines available.
If you wish to have some hard drink then you can try Haryana Tourism Resorts. One in the middle of city and other on the Rohtak-Delhi highway.