Yes you can do the aforesaid 

one and same person affidavit duly notarised should suffice 

however if consulate refuses to accept it then you have no option but to approach tehsildar for the certificate on the format provided by the consulate 

The process for obtaining a One and the Same Certificate can vary depending on the jurisdiction and specific requirements of the issuing authority.

In many cases, to obtain a One and the Same Certificate, you may need to follow these steps:

Prepare the necessary documents: This typically includes a same-name affidavit, a format or template for the certificate (provided by the Consulate), and any other supporting documents as required.

Write an application letter: It's common to include an application letter explaining the purpose of your request and providing relevant details, such as your name as it appears on the passport, degree, and transcripts. The letter should be addressed to the appropriate authority, which is usually the Tehsildar or the Sub-Divisional Magistrate (SDM) in your jurisdiction.

Submit the documents: Take the application letter, same-name affidavit, format/template for the certificate, and any other required documents to the Tehsildar office or the designated authority. Make sure to follow any specific instructions provided by the authority.

Pay any applicable fees: There may be fees associated with obtaining the One and the Same Certificate. Inquire about the fees and payment process at the Tehsildar office.

Follow up and collect the certificate: After submitting the documents and completing the necessary formalities, follow up with the Tehsildar office to check the status of your application. Once the certificate is issued, you can collect it from the office as per their instructions.

If the Tehsildar office does not provide the service or refuses to issue the certificate, you may explore alternative options. In such cases, it would be advisable to consult with a local attorney who can provide guidance on the specific options available in your jurisdiction. They can help you navigate the process and explore potential alternatives or escalate the matter if necessary.

The Tehsildar has nothing to do with the name change process.

Is there any specific mention about getting the affidavit certified by Tehsildar?

The Tehsildar has nothing to do with your name change.

The one and the same certificate is nothing but the same process applied for name change.

The affidavit should be notarised  by a notary public

You have to get the affidavit for the name change published in a local newspaper and if necessary a publication in the gazette publication.

You can submit the same along with your application by attaching the copies of the documents referred to herein above.

- Only an Affidavit will not serve the purposes, there may be requirement for publishing a public notice in the news paper 

- Further, you will have to submit the proofs of correct name as mentioned in the said Affidavit