Praise be to Allah.
It is not permissible to enter into riba-based transactions, even if your father tells you to do that. What you should have done when you found out that riba is haraam is leave the job, even if that would have made your father angry with you, because the Prophet (blessings and peace of Allah be upon him) said: There is no obedience to any created being if it involves disobedience towards Allah, may He be glorified and exalted. Narrated by Ahmad, 1041
But you are only responsible for the riba-based transactions that you did yourself or to which you were a party.
But if your father is the one who did that riba-based transaction and you did not help him with it or play any part in it, then you are not responsible for it, even if you were helping your father in his work that was financed by this riba-based loan.
What you have to do now is repent sincerely, regret what you did in the past and resolve not to go back to being involved in riba-based transactions. For more information please see the answer to question 162423 and 95005
The Muslim is not obliged to pay zakaah on his car or house if they are not trade goods, because the Prophet (blessings and peace of Allah be upon him) said: The Muslim does not have to pay zakaah on his slave or his horse.
Narrated by al-Bukhaari, 1463; Muslim, 983. For more information please see the answer to question no. 20057
With regard to paying off the debt from the jewellery, if the jewellery is the property of your wife, you and your father have no right to it, even if your father bought it with his own wealth, because it is no longer in his possession and it is not permissible for him to take it back. But if the jewellery still belongs to your father but he gave it to her as a loan, then he has to sell it and pay off the debts or part of them, because the Prophet (blessings and peace of Allah be upon him) said: Delay in payment of a debt on the part of a rich man is wrongdoing. Narrated by al-Bukhaari, 2288; Muslim, 1564. And he (blessings and peace of Allah be upon him) said: Whoever takes people's wealth intending to pay it back, Allah will enable him to pay it back, and whoever takes it intending to destroy it, Allah will destroy him. Narrated by al-Bukhaari, 2387
With regard to zakaah on jewellery, it is an obligation upon the owner. If it belongs to your wife, then she has to pay zakaah on it, if it reaches the nisaab (minimum threshold), which is 85 grams of gold, whether it is for adornment or otherwise. If your wife does not have any wealth other than this jewellery and she has to pay zakaah, then she must sell some of it and pay zakaah on it. For more information please see the answer to question no. 50273. The same applies to your mother.
There is nothing wrong with your wife or mother giving the zakaah to your father so that he can pay off his debts; rather that is preferable. For more information, please see the answer to question no. 43207
And Allah knows best.
Reproduced from Islam QA