The UPSC categorizes candidates for the Indian Forest Service (IFS) based on their performance in the exam's two stages: preliminary and main. The preliminary exam screens candidates through an objective-type question format, while the mains focus on descriptive answers relevant to forest conservation, biodiversity, and environmental policies. A crucial aspect of IFS selection is the interview stage, designed to assess candidates' personalities, motivation, and suitability for a role in forest services. Understanding the physical and ecological challenges in forestry is vital for candidates aspiring to join this service.