Please refer the below path to un-allocate the challan,
Login to greytHR application >> click on Payroll>> Admin>> Form 24Q>> Select the financial year>> Click on challans >> Select Quarter >> Select the month >> Click on un-allocate
After Un-allocating, Please refer the below path to update the challan details by excluding specific employees,
Un-allocate the challan for all the employees for required month.
Employee >> admin >> Excel Import >> Select Importer type as "Form24Q challan map importer">> Click on Import from Excel >> Download a sample file >> Update the Required fields >> Click on Upload file >> Next >> Check the Mappings >> Click on Next >> Import
Request you not to re-allocate after uploading and generate the FVU.