Ratna,
First you need to identify the account keys relevant to conditions types for VAT - Deductible as well as non-deductible. Only those account keys (processing keys) you have to maintain for the relevant withholding tax types. Transaction/account key VS6 shown in the above screenshot is only an example and may not be relevant.
Hint: To identify account keys you can use t-code OBYZ.
Regards,
Sunil