I already found out that our bike was based in the 1980s Trek Y Bike, and it was also different. I got the old trek bike from my grandparent's basement after 6 years of stagnation. It was kept there because the owner (my aunt) is working overseas. It was also my father's first MTB before he sold it to her.
TLDR: We're gonna restore this old school bike after repairing my road bike first (1 ½ years broken). My sister is going to pay for the new parts and will be using it.
I temporarily put the 24 inch tire as a rear support (not quite fitted but it'll do its purpose), it has 26 inch tires and 1.95 inner tube which are going to be replaced as well.
by ishmokey_man