Gangtok is the largest town and headquarters of Gangtok district at Indian state of Sikkim with population of 100,286. The average literacy rate of Gangtok is 82.17%. Lot of Educational institutions are found in Gangtok. List of IAS Coaching Centres in Gangtok. UPSC Aspirants can easily select the best IAS Coaching Centers in Gangtok. To add your UPSC Coaching Center details in this Gangtok. page freely, please mail your information to firstname.lastname@example.org. We have listed the Best Civil service coaching classes and Top 10 IAS Training Institutes in Gangtok.