Dirang‘s nearest airport is Tezpur Airport situated at 90.2 KM distance.
Nearest railway station to Dirang is Asan.
Nearest towns are Bomdila (20.7 KM distance), and Tawang (43.8 KM distance).
Source: http://wikiedit.org/India/Dirang/261221/
++
Dirang (རྡི་རང་།) is a good stopover on the way North.
Dirang Dzong (Fort): 500-600 years old houses and a 9th century prison.
Kalachakra Gompa: the oldest monastery in Arunachal Pradesh, over 500 years old.
Himalayan Culture & Tradition Preservation Society:
a learning center, also for tourists including foreigners
newest monastery
Sangti Valley: 15 km from Dirang; totally worth a visit.
Accomodation in Dirang:
1/ Hotel Pemaling: 130-180 rupees/day
Offers local Monpa ethnic cuisine such as red rice and chura kamtang. (Monpa cuisine is different from Tibetan cuisine.)
2/ Hotel Samdup Khang: B&B
Source: https://hippie-inheels.com/places-to-visit-in-dirang/
++
Thubsung Dhargyeling (LDL) Buddhist Monastery

Source: https://www.google.com/maps/place/LDL+Buddhist+Monastery/
++
Sessa Orchid Wildlife Sanctuary: established in 1989; has an area of 100 km2 (38.6 sq mi).
Sources:
https://en.wikipedia.org/wiki/Sessa_Orchid_Sanctuary
https://www.thehindu.com/todays-paper/tp-features/tp-metroplus/sessa-orchid-sanctuary/article28181403.ece