If I'll say hostel of boys then may it'd be wrong because we use 'of' for lifeless things like buildings 'Floor of hall.' So I found difficulty showing properties of plural live noun. I'm unable to show their properties as Boy's book, Girl's sack, Antonia's car. So 10 boys and their books. Just like that. So how can I do it?
You are right, "hostel of boys" is incorrect, but not for the reason you give. The preposition "of" can be used for living things: "What is the name of your child?" or "He is a king of the house of David."
No, "hostel of boys" is wrong for a different reason. When "of" is used with common nouns and without an article it often means "made of". For example: "a table of fine oak", "the board of directors". The table is made of oak. The board is made up of directors.
So, a "hostel of boys" would mean a hostel made up of boys. (Compare "a group of boys".) If the boys who were members of the hostel left, it would cease to exist. But that is not how hostels work.
You ought to say "a hostel for boys". The preposition "for" means that the hostel is provided for boys to use, whether they choose to visit it or not. Or you can say "a boy's hostel" as others have suggested.
I attended a girls' academy. The boys went to a boys' preparatory school. In the case of a hostel for boys, I would call it a boys' hostel. I wouldn't call it a hostel of boys. @Swapnil: Does this answer your question?
Unfortunately, your question stems from confusion over "of". While it can be used with inanimates, it is not restricted to them. "Of" can be, and is quite frequently used with animates and people.
Take these examples from Merriam-Webster:
I threw out that old shirt of yours.
She's a friend of my mother's.
He had the support of his family to help him.
the plays of William Shakespeare
We admired the courage of the young woman.