hey, i'm working on a UAV quadcopter,can anyone suggest me which is the best frequency to wrk with in india? i need video transmision and NLOS transmission since the objective of this UAV is to tranmit video in disaster hit areas,(include hilly areas also with trees),& it should cover a desirable distance of around 2km & less of power consumtion

Hello Arpita,
It is great to hear about your project . The quadcopter you are building must be first of all capable of carrying your camera along with its related transmission accessories. I guess you are using SK450 frame. The video transmission frequency you are talking about depends primarily on the type of setup being used by you for it. If you are using a proper FPV(First person view) kit then commonly used frequency is 5.8 GHz with operating frequencies of 5740 MHz, 5760 MHz, 5780 MHz, 5800 MHz, 5820 MHz ... Otherwise, you could go for commonly available wireless cameras in market... but... the range is limited in such cases . Also, I would like to add that FPV kits are quite expensive too . I would suggest you to mount a GPS module as well so that you could trace your quadcopter. 

Do mention about the type of control board being used by you.. also are you using a frame that comes with various RTF kits or a self made... post pics..