The literal translation of Jai, from hindi to engish is victory or victorious, and "Bhagavan, also written Bhagwan or Bhagawan, from the Sanskrit stem bhaga-vant, literally means "possessing fortune, blessed, prosperous" (from the noun bhaga, meaning "fortune, wealth","god"), and hence "illustrious, divine, venerable, holy. It is a greeting that basically means may the bhagavan - divine, prosperous, etc - in you be victorious.
A: Namaste and Good morning. How are you?
B:Jai Bhagwan. I am wonderful thank you.
A hindi version of the an ancient Sanskrit greeting "Namaste" which is still in everyday use in India and Nepal Himalaya. Translated roughly, it means "I bow to the God within you", or "The Spirit within me salutes the Spirit in you" - a knowing that we are all made from the same One Divine Consciousness.
Jai Bhagwan is used interchangeable with Namaste is some yoga classes.