Yes,you can hire a camp at Triund top but it is recommended to book in advance for your own safety. Triund attracts a lot of trekkers and gets crowded.So,it is possible that the campsites may get filled or you don't get your desired services.So,it is better to do a bit of research and book in advance.However,camping is closed at Triund top for time being and you can only camp at Dharmkot,which is the starting point of the trek.