Hi Divya,
Here are my suggestions:
For Finances: 6 months bank statements + ITRs for the last 2 years
There must be no recent large deposits in her bank account.... if there are then do explain the source of the income.... none of it should be borrowed.
Does she have FDs, shares, mutual funds, LIC, PPF? Foreign currency?
For Property:
Property ownership documents (Sale Agreement/Transfer Deed/Gift Deed) + assessment by a CA + proofs of current market rates (like prints of relevant MagicBrick pages or Times Property or Cushman & Wakefield reports.... that give indicative rates to back the CA assessment)
Also, latest property tax receipts (on her name)
For the rental property: Tenancy agreement + proofs of rental income credited to her bank account every month (cheque transfers, highlight this on the bank statement)
For Family Ties:
Proofs that your brother, his family and your grand mom live at the same address.
If your mom takes care of your brother's kids (if he has children) + your grand mom then mention this in the Cover Letter.... and your mom must return to these responsibilities
For Purpose of Visit:
She can draw up a rough itinerary for sightseeing + meet your friends, etc.
Try to keep her visit to 1-1.5 months.
Although it is not necessary, I suggest buying Overseas Travel Medical Insurance (where cancellation is possible for a small fee).... for the duration of her visit.... and submit proofs with the visa application.
Did you mention that you're getting married? Did you provide the wedding invitation/other proofs? What documents did you provide as host?
Does she have to return to India by a certain date for some event or reason? Does she have any other responsibilities/commitments to return to?
Has your mom traveled abroad earlier?
Another point:
Do be careful of the words you use in the invitation letter/her cover letter..... you should not write *at least 2 months*..... be definite because an indefinite/open ended plan could mean that she will overstay her visit
Cheers