connecting my anroid phone to ddj rr

You'll have to purchase a minijack-to-RCA cable, connect it to one of the inputs on the back of the RR, then when you want to play from their mobile, plug the jack into the headphone port, and switch the channel input selector to LINE.

Personally, I don't just let people at the party play music from their phones, but that's just me as the DJ speaking.