Bands are usually placed on the birds left leg - though strictly speaking it really doesn't matter unless it is for official purposes. If it is then I should hope you wouldn't have to ask.
The question itself brings up many curiosities: Are you breeding them? Where did you get the bands? Did that source not give you any information?
thanks for the reply , the reason i asked is that i have 2 green cheeked conures and they have bands on different legs and i was told that left leg female right leg male , how true this is i dont know .
dave