Dear Mr. Kumar,
Difference between back wages and unpaid wages
First, there is a difference between back wages and unpaid wages. Back wages, literally and legally, mean the wages for the period of non-employment declared by the competent authority to be deemed as a continuous period of service after the adjudication of the issue of alleged illegal termination of employment by the employer. On the contrary, unpaid wages mean denied wages or wages not paid by the employer for whatever reason.
Claiming back wages
The claim for back wages can be presented before the Labor Court under section 33-C(2) of the Industrial Disputes Act, 1947, apart from filing a complaint to the area conciliation officer for the prosecution of the employer against the offense of non-implementation of the award under section 29 of the IDA, 1947.
Claiming denied wages or illegal deductions
A claim for denied wages or illegal deductions can be filed under section 15 of the Payment of Wages Act, 1936, before the designated authority under the Act. If it is only unpaid wages pertaining to any wage period, alternatively, a claim may be filed to the appropriate Government under section 33-C(1) of the IDA, 1947, and the Government, after an inquiry, will issue orders to the concerned District Collector for recovery under the Land Revenue Recovery Act.
Employer's defense
The defense of the employer in this regard can be the gainful employment of the workman elsewhere during the period of non-employment in case of orders of termination set aside as illegal by the competent authority. Here, gainful employment does not mean self-employment by the affected workman by doing odd jobs to eke out a living during the period of his non-employment. Please take note that "competent authority" means here a Labor Court or any other appellate authority appointed under any establishment-specific law like the Shops and Establishments Act to hear and dispose of the cases of termination in violation of the relevant provisions of discharge under the respective Act.
Another defense is "No work - No Pay" if the non-employment is ascribed to the voluntary absence of the workman or non-functioning of the entire establishment due to the operation of any law like the Disaster Management Act, 2005.
I have not included the case of non-payment of wages by an employer in violation of the orders of any High Court under section 17-B of the IDA, 1947, for the simple reason that in such a situation, the appeal filed by the employer against the orders of reinstatement by the trial forum would be summarily dismissed by the Court on this ground alone.