बधाई हो (Badhai Ho)
This phrase is used for a wide range of occasions, including:
* Birthdays
* Weddings
* Graduations
* Achievements
* Successes
You can also use other phrases depending on the specific context, such as:
* शुभकामनाएँ (Shubhkamnaye) - Best wishes
* आपको बहुत-बहुत बधाई (Aapko bahut-bahut badhai) - Congratulations to you
* आपकी सफलता के लिए बधाई (Aapki safalta ke liye badhai) - Congratulations on your success
The best way to choose the right phrase is to consider the specific situation and the level of formality you want to convey.