There are notaries in the UK who can draft an affidavit for you. Their prices vary so the best option is to refer to Yellow pages ( www.yell.com
- search for notaries nearest to your postcode), find a notary nearby, contact them to check for prices based on your requirement. You can get your public affidavit drafted and notarised by them.
Google "Affidavit Template" and you will find quite a few templates. The problem you might have is which template should you use and I do not know the answer to that, hence my recommendation above.
Now the last paragraph (specifically this line - has to be certified by first judicial magistrate in India
)) of your post makes me think you might need to get your public affidavit made and notarised in India. If you have friends or relatives in India, ask them if they can do this at a local court/by contacting a local lawyer on your behalf. They will then have to post the document to you in the UK.