Yes, you can update a challan in filed e-TDS Return. For corrections in PAN masterpersonal informationdeductee details, and challan details, there is no need to request for Conso file (file correction statement). 

Payer/ Deductor can make a correction using the service ‘Request for Correction’ on TRACES. Payer/ Deductor can perform the correction in Challan Details provided the regular return is processed and DSC of a responsible person is registered with TRACES. 

If not then the payer/ deductor needs to file a correction statement (Revise Return) by downloading Conso File from TRACES. 

Read More: How to update challan on TRACES?