Father Daughter and Son in Law duping son financially and illtreating mother

Dear sir/ Madam, We are in a fix here with a peculiar situation. I have been working for past 20 years and in past twenty years I have been financially helping my father in his business which has always been running in loss. Right from when I started earning i.e. 20 years back outside India, my father started blackmailing me saying if I don't look after him I will be jailed, not because he needs the money but because I am the son. I started paying his invisible money lenders every now and then in lumpsum amounts which were never accounted for. There was never any return or accountability of those. He owned a shop which he refused to close down inspite of losses while taking money on a regular basis and giving it away to I donot know whom. Secondly he wanted me to fix the bungalow(ancestral property) and renovate it which I did from my earning. Again he duped me of lakhs of rupees without any accountability of the expenses and the house money went into random hands. Later I came to know that the cash credit amount that he has to repay the bank against which he took loans for his business has risen up from lakhs to many lakhs without my knowledge. Later he got his share of other ancestral business from his brother and instead of repaying the cash credit amount to the bank he bought a house for my sister without my knowledge. All this time I had been financially helping my father to run his household. Later the cash credit amount tripled yet he did not pay back. Today my mother is undergoing an ageing psychological problem though its being treated well. But recently my sister and her husband made them move from that property and take up a rental house in their locality in the pretext of taking care of my parents. I came to know last to last month from an outside source that my father is again trying to sell of this property in secrecy without my knowledge. This house has my investment. Meanwhile my father and my sister and her husband started mentally torturing and harassing and physically abusing my mother and telling everyone around that she needs an asylum. However her doctor has no such claims, she claims she is much better. My father and my sister and her husband now are trying to shove my mother off their shoulders. I stay outside India and am never told what they are ding with my money. Today I am scared for my mother as I need this job to sustain my family and my mother is not going to get her visa here. Hence even if I go and stay with her it does not solve the problem. Recently my father has sold off his business, has kept enough money in the bank yet asking for money while he has not made my mother a joint account holder and just a nominee. Besides my brother in law has blocked my contact and defamed me amongst my friends and contacts saying I donot take care of my father. While all this time after selling off the business my father gave away lakhs of rupees to his former employee and to another friend of his without my knowledge.