The first counselling seat allotment date depends on state board or university process, often it is a few days after choice filling

1, Tripura Board or Tripura University usually open seat allotment list around late July or early August

2, Online counselling process finishes, then they publish seat allotment PDF on official portal

3, For arts stream the first list may come in first or second week of August

4, You check official notification or login with your application number to download allotment

5, After allotment you must report college within given time with documents and fees

You can check general seat allotment steps here

https://www.careers360.com/articles/seat-allotment-process-for-college-admission