IndiaRO is free with Cash Shop, you could also play on the *coughyouknowwhatcough* servers, but it's not the same, they lack content, are empty and it just isn't the same.
Also, it's not THAT expensive, compared to other P2P games, so you might as well consider paying for it. On the other hand the P2P + Cash Shop payment model they applied to most of their servers not too long ago is a very bad idea in my opinion. :x So why pay a monthly fee if you can play on inRO for free?
It's your choice though.