Hello,

The Indian Forest Service (IFS) is one of the Civil Services Examination conducted by Union Public Service Commission.

The IFS officers are recruited and trained by the Central government but their services are placed under state cadres, and they have to serve both under the state and Central governments.

There are total 90 vacancies every year.

In 2015 and 2016, 45 officers each were selected for the IFS, but the next two years, the numbers fell to 42 and 30, respectively. “The IFS is one of the smallest cadres in the country.

https://competition.careers360.com/exams/upsc-ifs

You can refer to this link for more information

Hope this helps!!