Statement I is correct: Hollongapar Gibbon Sanctuary in Assam is home to Western Hoolock Gibbon, listed as Endangered on the IUCN Red List.
Statement II is correct: They have long forelimbs specialised for brachiation (swinging between trees).
Statement III is not correct: Hoolock gibbons are small/light-bodied apes (around 6 kg), not heavy like gorillas. They are agile arboreal apes, not "tree climbers" in the gorilla sense.
Source:
https://www.wwfindia.org/about_wwf/priority_species/lesser_known_species/hoolock_gibbons_/
The Notification for the Civil Services Examination, 2021 was released by the Commission on March 04, 2021. The notification contains all the details related to the examination dates, number of vacancies, eligibility criteria, syllabus, application process, fee, exam centers etc. The exam is being conducted to fill in 712 vacancies as listed in the notification with 22 vacancies reserved for Persons with Benchmark Disability. The Preliminary examination will be held on October 10 2021. Candidates can visit the Commission’s website  to fill the application form. Detailed instructions for filling up online applications have been provided on the website. The application window was closed on March 24 2021. The admit cards for the Preliminary Examination were made available from September 16 2021. The admit cards can be downloaded from the Commission’s website on the above mentioned link.