Hai everyone;I need everyone's suggestion for this.Please

using the term lakhs, you are most likely either in India, Sri Lanka Myanmar or Bangladesh or Pakistan. Given that, I am not sure how many of use understand enough of the law in any of those countries to be able to tell you what you might be able to do.

The only reason I know this is my husband does some work in India.

Good Lord, I shouldn't try to type before having coffee.
First, that should read 10 lakhs (assuming this is your monetary units).
then, it should read "that still means that there are 4 shares and ONE of those is to be split between a few people." Meaning that if her heirs were entitled to her share of the estate you are separating now, her heirs would only be entitled to SHARE her one share of the estate. Say it's worth 40 and there are you, your brother, your mother and your grandmother. That would leave 10 (or the equivalent) to each of you. If she does not want to settle, her heirs will be entitled to share her original portion of 10 - regardless of how many heirs of hers there are. Now, if she refuses to settle and the estate consists of real property, if that property increases in value by the time she passes, then they will be entitled to a share of the newly evaluated estate. I don't know how it works there.

Okay, so if I am getting this right, she can either have what amounts to 10 lakes now, or your family will have to disburse that same amount to her beneficiaries when she dies? I don't know how you do probate in your country,but here a share is a share. For instance, say my grandparents die and leave an equal share of their estate to each of their 4 kids. Then my father dies so they am mend the terms to say that me and my siblings share my father's share in the estate. That still means that there is 4 shares and on on rhose is to be split between a few people. Her share shouldn't be more just because of her beneficiaries, they would just need to share on portion of the estate. Why is she saying that she wants 50 and why does she think she can get it if the registrar says she is only owed 10?

i don't know what country you are in, but in US, you most likely would have to take it to court. she wants to sell her part to you(and rest of family). if the court ordered the land be appraised for value, you would know exactly how much it is worth, and then offer your father's mother that amount. if not, she has the right to keep it.
most likely, you'll have to go to court over this.
its not anyone's business why you wish to take her part from her, but it seems odd when anyone tries to rearrange things like this. your father left the land divided to all 4, not just the 3 of you. this is going to cause hurt feelings.