New OCI application steps to take

Hi

I'm in the process of applying for an OCI card and was wondering the steps I should take?

My mum came to the UK in the 60's and gave up her Indian passport.

From what I have read the steps should be: can you confirm these are correct ?

1 gather documents and find a notary to validate my mothers original Indian root citizenship

2 the documents I have are Certificate of reg in UK inc Indian birthplace, marriage certificate, old English passports, my birth certificate and passport.

- are these enough evidence/ should I ask the notary or my local VFS centre for advice on which documents I need ?
does anyone have any links to exactly what documents are enough?

Thanks