TDS deductor

it will come under b2c

It should be B2B as you wud also be availing TDS claim from this GSTIN.
Also TDS deductor shall also need to mention its input supplies where TDS deducted. Mentioning GSTIN by you would help in matching too.
Also registered person includes all types of registrations whether as TDS deductor or ISD. So in that ways as well it should be B2B.

It is compulsory to obtain GST registration for the person who are liable to deduct TDS as per the provisions of section 51 of CGST Act, 2017. Threshold exemption limit is not applicable to such persons.

Unique feature of GST registration, for person liable to deduct TDS, is that PAN is not mandatory while obtaining GST registration, however, GST registration can be obtained on the basis of existing Tax Deduction and Collection Account Number (TAN).

It will be cover under B2B , transaction , to whom you are supplying have a GST No. & TDS is going to reflect on the portal of supplier , Matching can be done only when its B2B transaction