If its 2 tons and they are the same stand then yes. The stands are distributing the weight. So unless stated otherwise by the manufacture it means the PAIR can handle two tons. So if you have 2 two ton stands holding up just the front/rear then its more than enough. If you wanted to jack up the entire car on all four using 4 two ton stands that would also be fine. Just make sure the brand you have, or are thinking about buying is not on some recall list that will get you killed and make sure they have a safety lock pin/insert.
If you're only raising one end of the car (the front end) then the stands are supporting far less than the total weight of the car. Probably less than 1000 lbs. each.