Is it possible to obtain loan on a property acquired from my father? Can my children object?

I own a property that used to belong to my grandfather and later my brother, my brother gifted me the property and now want to obtain a loan from a bank. Is the approval of my children necessary to get the loan from the bank? If I do without their approval, can they file a case against me?
Sorry, I made a mistake in the details, the property belonged to my father not my grandfather.

What is the minimum age to avail car loan?

I just turned 18 in September (2007, obviously), and I want to buy a car. My monthly income is well over 80,000 and I was wondering if I can avail car loan in India.

If yes, then which bank?
I just checked out some bank websites. They all say 21 is the minimum age. Ouch!

Any clues?