Unlocked iPhone 5 in India

So my cousin in India asked me to buy an unlocked iPhone 5 for her from the US to give to her when I go and visit in a few weeks. I just wanted to know if anyone knew the process behind activating an unlocked iPhone 5 in India that was bought in the US (I've heard that the nano-SIM makes the process different/more complicated).

Do only certain providers in India support unlocked iPhone 5s right now or do all providers there now have the nano-SIM technology to activate it? Thank you all for your responses in advance.