Plot purchased through development agreement and general power of attorney

Your mother was given the right to sell and transfer the property, but the Development Agreement and GPA are in force and the principal of DA cum GPA is alive?

I am not sure about whether they are alive or not but I met them 3 years before.

If your mother in the capacity of power of attorney agent is desirous of selling this property then she must confirm that the principal is alive and a life certificate about him also to be obtained

Without that she cannot transfer this property to anyone by a registered deed. 

Since your mother is not the actual title holder she has no right to transfer the land.

I understand your concern. To transfer the property title to your name and your elder brother's name, you'll need to follow these steps: 1. _Execution of Gift Deed_: Your mother can execute a gift deed in favor of you and your elder brother. This deed should be registered with the Sub-Registrar's office. 2. _Registration of Gift Deed_: The gift deed should be registered under the Registration Act, 1908. 3. _Stamp Duty_: Pay the required stamp duty on the gift deed. 4. _Mutation_: Apply for mutation of the property in your and your elder brother's name with the local authorities. Regarding the issue with the 7/12 document, it's a revenue record that shows the ownership and other details of the property. If the developer has not handed over the original 7/12 document, you may: 1. _Obtain a certified copy_: Get a certified copy of the 7/12 document from the revenue department. 2. _Apply for a duplicate_: Apply for a duplicate 7/12 document with the revenue department. 3. _Seek legal advice_: Consult a lawyer to explore other options. Additionally, since the property was purchased through a development agreement and general power of attorney, you may need to: 1. _Get the GPA revoked_: Get the general power of attorney revoked by the developer. 2. _Execute a new agreement_: Execute a new agreement or sale deed to transfer the property title to your name and your elder brother's name. Please consult a lawyer or property expert to guide you through the process and ensure compliance with all legal formalities.

What can not be done directly cannot be done indirectly is the issue here, that is the Mother Deed itself is not perfect, because government prohibit sale of agricultural land. Development agreement and POA cannot create conveyance of immovable property, but since the original owner is alive you have the opportunity to correct the lacuna in your title.

Since sale of agriculture land below 10000sqft is not allowed in Maharashtra right now, what other paper I can make from the landowner to get title of land? Can I make Release deed? 

Note: We have also shown Value consideration in PoA as well as Development agreement. 

Whether Maharashtra government or local competent authorities have changed its usage and declared subject "agriculture" land to be "development" land  ?

Release deed cannot be made in case of a piece of land purchased for development since relinquishment of title can be made by a co-owner / legal heir in favour of another co-owner for inherited /ancestral but not self-acquired property. 

What should we do now?

We have paid the total cost of the property to the owner through Development agreement which is a registered one. Also it is written by the Seller in agreement that we have received the entire amount and henceforth we or our legal heirs will not ask for any single penny and this land belongs to you and you can execute Sale deed on your name( for which they have given us GPA).

I met Talathi and asked him, he said that your land is in R Zone. I don't know how can we get the title of this land. I want solution/way.

Admittedly, the law has been evaded. Solution, if any, lies only within the provisions of the law you have tried to evade. Only a local advocate or expert could be of assistance to you in the given context.

To my knowledge, the provisions of  Maharashtra Prevention of Fragmentation and Consolidation of Holdings Act, 1947 and the  Maharashtra Agricultural Lands (Ceiling on Holdings) Act, 1961 applies to the given facts.