• Claim in father's property

I had purchased a 50 sq. yard plot in Delhi in 2003 and had its papers (General Power of Attorney) in the name of my mother and father. I have borrowed the money (1,15000) from one of my relatives for buying this plot. This money had come through DD for three different amount totaling (1,15000) in my own SBI account. 
Later on in the year 2005 I took the initiatives of constructing the house too (ground floor) and again arranged money through different sources that included some part of departmental personal loan in the name of my father. I extended my full support to pay off the debt either by giving cash amount to my father or spending for household expenditure in lieu of my father's household contribution.
I got married in July 2006 and we due to lack of space in house, I constructed first floor entirely at my own without any support from any of my family members.
We are three siblings I am the eldest one. Besides me one sister who is married and settled in Pune and younger brother who is unmarried (living relationship) and well settled and has financially much sound status in comparison to me.
In the year Dec-2007, my father got retired and took the responsibility of all household expenditure. However, soon after three months they separated me and asked to live at my own at first floor and didn't seek any financial help from me. In between my father had got his after retirement money (PF & Gratuity) and that's why they did not want my support anymore. However, as and when required, I kept on helping them financially and otherwise whatsoever required.
Despite all above, our relationship (me and rest of my family) become worse. Now, my mother-father and brother want me vacate the house and not ready to give me my share. They're threatening me to sue me and expel me by the intervention of court in case I don't vacate at myself. 
I have asked them I am ready to leave the house and demanded at least the amount what I've spent on house construction and purchasing of plot. But they're not ready to give that too.
I am well aware of the present law that being self acquired property, my parents are not bound to give me my share nor I can claim. But the fact is that, they've got this property almost for free and I have spent my hard earned money on it, be it buying of plot or construction cost.
Recently I came to know that, my parents and my younger brother are planning to demolish the house and want to construct builder floors to sell them to make easy money.
Now, I want to know that is there any way I can protect my interest or stop them by doing so?
Here I'd like to mention that, the payment for plot was done by cheque from my account in 2003. Can it be of any help?