Equal pay CTC and IBA employees for same work in same scale

We are employees of a private sector bank employees in 2009_2010 under the CTC pattern of salary structure.we are facing issues of disparity in salary. Please see below sequence of event that have taken place to understand the case better. 1. In march 2012 new management issued circular and offered to convert CTC employees to IBA salary structure.All most all CTC employees applied but only 60% were converted to IBA.No reason was given by management about selection criteria. 2. In may 2012 Remaining CTC employees were verbally asked to resign and then later salaries of CTC employees under scale 1 2 3 4 was reduced by new management upto 40% while salaries of employees under IBA was not reduced at all. 3.2013 another 150 clerks were converted to IBA after exams. 4. In April 2014 management issued circular than bank only follows the IBA pattern of salary structure and hence in order to be in conformity with IBA rules every employees designation in both CTC and IBA was lowrrered one level e.g. all manager was now assistant managers and senior managers became manager.. 5. Since 2010.There Is No increase in salary for CTC employees till date except 10 % in 2016. We have given several letters to management about our issues but nothing has happened. Please let us know if we have a legal option as constitution also tAlks about equal pay for equal work as per recent Supreme court judgement. Here we are all in equal scale with our IBA colleagues. Some CTC employees in scale 2 are managing and supervising fellow colleague's in IBA but are paid just half what an IBA colleague in paid in scale 1.