When should I go for my visa extension if my tourist visa expires on June 5th, and can I get a 30-day extension?

The user inquired about extending their 60-day tourist visa, which expires on June 5th, noting that June 3rd is a holiday. They asked if it is acceptable to visit immigration on June 6th for the extension and whether a 30-day extension is available for Sri Lankan passport holders. In the comments, it was clarified that Sri Lankan nationals are only eligible for a 7-day extension, as a 30-day extension is not available for them.