History:

Bhai, the surname itself hints at a family connection, maybe even showing who someones father was. This surnames spread probably follows usual family migration patterns. Think of families moving within an area because of things like available land, jobs, or marriage. Over time, these small moves add up to the surname spreading far and wide. People moving for better jobs or education would also play a part, as would any forced movements affecting the familys location.

Description:

Its basically a name ("Satish") plus a respectful title ("bhai"). Satish is a popular name among many Indian Hindus. Youd need more clues, like where theyre from or their family history.