Shaadi ke Side Effects is a Half Hindi-Half English name which translates to 'Side Effects of Marriage' in English, and in Hindi would translate to 'Shaadi ke atirikt prabhaav'.
Of course, that would make a very tough name if all Hindi, and also side effect is a term almost always used as-is in spoken Hindi as well.
Shaadi ke Side Effects is an upcoming comedy starring Farhan Akhtar and Vidya Balan, to be directed by Saket Chaudhary, who also made Pyaar ke Side Effects earlier.