Hey Sindu, Manli is good. Tripoto offers low budget packages for Manali. Attached with comments are few packages offered by Tripoto. Please take a look, fill the form and someone will get in touch with you. Thanks!
Hi friend, i would suggest you to book a trek with Youth hostel, its a NGO and so the costs are comparatively cheap.
they arrange you fir everything and you might think that its less cost and so the quality would be poor, but the quality of stay, food everything is more than what you can expect for. Other than that if you want to travel and explore just for fun, i suggest go to kasol first and then to manali, there are easily available cheap hostels where you can stay.