Hi Adil,
Surely You can start from tele sales & gradually build your call center on that, I would support such an idea, specially when you are new in this field, you will get to learn alot, and this will be first hand knowledge.
It also depends that how much volume you can handle or what kinda of product you are catering to, if its a fast selling product then may be in next one year you will need to expand.
Incase you need my help let me know.
Good Luck to You.
Regards,
Aezad Ahmad