Yes, Opfin will permit you to execute payroll for past months for which TDS returns have already been filed. However, we cannot change the TDS returns, and thus this might lead to inaccurate data for the employees for whom payroll is executed later. Especially if TDS is being deducted, the employee(s) will not see it in their Form 16. In such a case you will need to get a correction filed externally.