(A) Unlawful Activities (Prevention) Act (37 of 1967) , S.45(2), S.52— Unlawful Activities (Prevention) (Recommendation and Sanction of Prosecution) Rules (2008) , R.3, R.4— Sanction for prosecution under UAPA - Challenge against validity of -Appropriate stage - Validity of sanction should be challenged at the earliest instance available, before trial Court - If such a challenge is raised at appellate stage, it would be for person raising the challenge to give reasons for bringing the same at a belated stage - Such reasons would have to be considered independently so as to ensure that there is no misuse of right of challenge with aim to stall or delay proceedings. AIROnline 2019 SC 1131-FollowedAIR 2001 SC 2547-Followed2023 Cri LJ 3965 (SC)-Followed (Para 17 41 51.1) (B) Unlawful Activities (Prevention) Act (37 of 1967) , S.45(2), S.52— Unlawful Activities (Prevention) (Recommendation and Sanction of Prosecution) Rules (2008) , R.3, R.4— Sanction for prosecution under UAPA - Timeline for - Whether mandatory - Timelines provided for recommending and granting of sanction are mandatory in nature. Constitution of India , Art.21— Interpretation of Statutes - Strict Construction Of P....