Shuddh is Hindi for Pure, Desi here is used for countryside, as an adjective, and Romance you know about. So Shuddh Desi Romance means Pure Countryside Romance, or Pure Local-Styled Romance.
Shuddh Desi Romance is an upcoming Yash Raj production starring Sushant Singh Rajput, Parineeti Chopra, Vaani Kapoor and Rishi Kapoor.