The share of property inherited by your father from his father becomes your father's self acquired and his own property. 

Nobody has any rights in it to claim any share in it. 

Since your brother is indulging in atrocious activities using his muscle power or masculine domination in the family,  your father can take action either to distribute his property equally or as per his choice  or instruct your brother to not to indulge in activities causing injustice to you both. 

If your brother is not listening then your father can go ahead and distribute his properties as per his desire and decision by executing a registered settlement deed. 

You can convince your father about it and prompt him to take swift action in this regard. 

If it was not equally between all legal heirs then it will still remain to be ancestral and person can claim share 

1) sell the plot standing in mother name . Issue notice to brother to handover title deeds of plot 

2) father should execute deed of family settlement or partition for division of plot among you and your siblings 

3) your father should put his foot down and ask him close the portion of land used as classroom 

Once deed of partition has been executed duly stamped and registered your father is absolute owner of land 

he is free to sell the land or bequeath it or gift the land during his lifetime 

ask father to execute deed of family settlement during his lifetime 

No,  it is not ancestral property in the hands of your grandfather or your father hence the grandchildren cannot claim any share in the share of your father share of property as a coparcenary rights. 

1.  Assuming that the land was originally self acquired by your great grandfather (grandfather's father) and he gave a large piece of land to your grandfather through a registered deed, then in your grandfather's hands, it has to be treated as his seperate property having the characteristics of self acquired property and not his ancestral property. Then the registered Partition Deed dividing the land amongst his sons' is in order.Based on the partition deed, the land acquired by your father is his separate property and during your father's lifetime he will be independent to take any decision regarding this property including gifting or selling or executing WILL in favour of anyone.

In case your great grandfather had given a large piece of land to your grandfather without a registered document and the name of your great grandfather still remains intact in the property documents, then the property qualifies to be ancestral property.

2.  You and your sister may convince your father to execute registered Gift Deed/Partition Deed/WILL demarcating clearly the boundaries amongst siblings.

3.  To stop/prevent construction on your father's owned land, let your father bring Injunction Order as the property is in your father's name, which has to be treated as his self acquired property and your brother, without your father's permission, can't unilaterally construct buildings, including school for poor kids.

4.   Regarding the plot in your mother's name bought by your father, it's not clear as to whether your mother is dead or alive. If dead, then whether she died intestate (without executing a WILL) or testate (executed WILL) naming the beneficiaries to her property.

5.  Assuming that your mother died intestate, then her property would devolve equally to her husband and children. In the instant case, 1/4th undivided share to your father, 1/4th undivided share to you, 1/4th undivided share to your sister and 1/4th undivided share to your brother.

6.   If your brother tries to sell this plot to a prospective buyer, then send a legal notice to him so that the issue could be resolved.

1. Both the properties belong to your father who is alive.

2. For the first property, you and your sister can convince your father to register a gift deed or Will gifting/bequeathing equal share of the property with metes and bounds amongst all his three children.

3. Once it is gifted you will become the owner of your share and if it is willed, you will become its owner legally after the demise of your father.

1. You could have called it ancestral property had there been no flow of title of any share of the property from your great grandfather to anybody thereafter.

2. In the instant case, it is not an ancestral property.

Here's some guidance on the property division situation:

Regarding the Farm Land:

Inheritance Rights: Since your grandfather divided the land and your father received a share, you and your siblings most likely have inheritance rights to that portion.Negotiation or Mediation: The ideal scenario would be to have an open and honest conversation with your father and brother about dividing the land fairly. Perhaps a mediator could facilitate a productive discussion to avoid putting stress on your parents.Legal Action: If communication fails, consider consulting a property lawyer specializing in inheritance. They can advise you on the legal options for partition, which might involve filing a lawsuit. However, legal action can be lengthy and expensive, so explore all possibilities before resorting to it.

Your Brother's Construction Activities:

Consent for Construction: If your brother hasn't obtained your consent for building on the property, it might be considered trespassing. A lawyer can advise on the legality of his actions.Impact on Land Value: Large-scale constructions might affect the land's future value when divided. It's crucial to document these constructions with photographs and receipts.

The Plot Nominated to Your Brother:

Nominee vs. Owner: Being a nominee on a plot doesn't necessarily grant ownership. Your mother likely remains the legal owner.Selling the Plot: If your father wants to sell and share the proceeds, but keeps delaying due to market fluctuations, it creates a complex situation.