Salary not paid and blocking new opportunities.

Dear Sir /Madam I am Mithun working as a desktop engineer in ITCons e Sol private ltd. Which is located in noida . where I and my friends are working in different location s across India for a project in the above company since march 2016 onwards. After one year our salary was reduced and still we started working in this company. But from last three months salary is not paid to hundreds of employees working in different locations across India. If we ask them client didn't pay money and so we are holding r salary. We sent a notice and said we will not work till we received our salary and asked them to payvfor whatvwe r not present. Then one month passed and no response till now. As of this another company is a offering us to work with them for same project and this was known by our company. They are sending mails that it is unlawful act if u work with others. If we resign without paying salary they mention in relieving that full payment is made to you. This happened to one of the person in our group. That full payment is made. Our online salary slips were deleted from the company website. They are not paying salaries , not relieving us and blocking our new opportunities. How many days should we waste on behalf of them . Please help us. Hundreds of employees are suffering in this case. We work in different locations in different state across India. Please help UA what to do? Thanks and regards