In an episode Mishra Ji mentioned that Annu's birth year is 1998. In real life Harsh Mayar who plays the character of Aman Mishra was born in 1998.
Gullak is known to have use minimum locations. The main location is house, In season 2 only 4 other location is used other than house.
The voice for Gullak is given by Shivankit Singh Parihar.
Harsh Mayar who played Aman Mishra is actually at least 10 years older than his character. By 4th season he is still in school but in actual life he is married.
Lucky was the only character who appeared in this season but was present on season one. He was mentioned only on phone calls by Annu.