Paying zakaat but having a joint liability to pay off

More over after paying zakat if its wajib, I will still get left with some amount. So when the month of zil-hujj comes should I offer Qurbani also as I have paid zakat so qurbani has become obligatory for me also. This is my personal money and not included with others but yes I have to contribute in paying off the loan as we all took it from our brother in law in buying a flat so it the responsibility on all of us to contribute in paying off the loan.