What are the rights/duties of man in terms of monetary help, etc., to be provided to father and mother, wife and brothers and sisters, if any, and in-laws?
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Each one of the categories mentioned in your question has some rights over you. But these rights differ from one person to the other.
The wife's rights can be summarized in spending on her as people spend on their wives in the area where she lives, clothing her and providing shelter for her. The Prophet said in the Farewell speech: “Their (wives) right upon you is that you should provide them with food and clothing in a fitting manner.” [Muslim]
The dowry (bridal money paid to the woman at the marriage contract) is also among her financial rights.
As for the parents, they have the right of expenditure provided their son has more than the daily expenditure needed for him, his wife and his children, and provided that his parents are poor. But the right of the parents are great as Allah linked worshipping Him with being dutiful to the parents as He Says (what means): {And your Lord has decreed that you not worship except Him, and to parents, good treatment.} [Quran 17:23]
As for brothers and sisters, one is not obliged to spend on them unless he spends on them for their kinship relation to him, pursuant to the saying of Prophet : “And keep ties with your Arhaam (close relatives) (by getting in touch with them and helping them).” [Al-Haakim and Al-Muanad]
As for in-laws, they have no specific financial rights over their brother-in-law. This is a brief account on the rights due on the person to others. For more details one should read the books of Islamic Jurisprudence.
Allah knows best.
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