But i cannot find the sim slot.
What exactly do you mean by that?? its suppose to be on the right hand side :/ , unless your brother bought a CDMA version which I think doesn't have a SIM slot.
*st3.gsmarena.com/pic/vv/reviewsimg/apple-iphone-5/gal/gsmarena_014.jpg
EDIT: can you post the model number from the user manual/back of phone. if its a CDMA model then you need to check with CDMA providers like reliance and MTS. if they cannot provide any support then i'm sorry to say that you have bought the new iPod Touch.