Salary Confiscation citing contract letter

Dear Sir I worked as a Senior Language Teacher with a private school at Nainital in Uttarakhand from Apr 2012 to Apr 2015. I received my offer letter on school's letter head, which also mentioned about a Contract Letter attached on plain A4 sheets. Organization had a policy of deducting sum of 3 thousand rupees from employee's salary every month, in the name of Security Amount, until it accumulates to 3 times of his monthly salary and the same is paid back with bank interest rates at the end of its maturity. As I had to resign from my duties due to health issues of my father, in between. I resigned on 4th Feb 2015 through email and came on one month notice period, as session finishes on 30th March every year. Though initially organization made efforts to retain me but due to my insistence i continued my one month notice period (Same one month notice was served by all other employees also who had left during my tenure, before me) However at the end of my notice period my father passed away and i had to return to my home town Ghaziabad (UP). Later on i was told that my so called 'Security Amount' is confiscated which amount to Rs. 1,12,987=00 and along with they also denied to return my one month extra salary that was due in lieu of working during vacation period which amounted to 30,000 approx. Which later on was paid to all other employees who had worked with me during that term. On the top of it, to be preventive, so that I dare not even peruse it further, they got one notice slapped on me by their lawyer of paying 30, 000 more, due to the caused damaged for the breach of contract citing some clause of the contract letter. Another interesting fact is that that I am not the only victim of the above said unfair practice but amongst one of the five people who have undergone the exact mental and financial trauma. they also left the jobs in the same financial year. I request for your kind suggestions on following or any other important aspect according to you. 1. Whether private organizations have rights to deduct share of employee's salary in the name of 'Security Amount" 2. Whether such contracts which are signed in close cabins hold any validity as they bind an employee. 3. Do you see any scope for all us five people to go ahead and reply to the organization and claim our denied rights. Kindly suggest, you would be great help Thanks Abhishek Sharma