First of all answer the following questions:
1) How was the 3 acres of land allotted to you and by whom, whether your father or grandfather?,
2) Out of 18 acres that belonged to your grandfather, whether his six children were allotted their shares equally, i.e., 3 acres each?, if so how did you get this 3 acres of land, because your father himself had acquired only 3 acres?
3) Where from you got additional 2 acres of land?
4) What do you mean by stay order and against whom?
5) Have you already approached court for partition?
6) Whether you are aware of the contents of the notice sent to you? If so, what was the purpose of issuing notice to you and by whom?
7) Have you already engaged a lawyer, if so, whether he filed a suit on your behalf?,
If you have the gift deed in your possession, the 3 acres allotted to you, if not specified properly, it will remain in the undivided property.
Now answers to your questions:
1) Whether this portion was allotted to you as a share in the undivided property, if so you can seek for an appointment of advocate commissioner to identify your share of property and allot the same to you.
2) After sending a legal notice, if they did not respond, you have to approach court alone and cannot send a stay order on your own, by the way stay is for what?
3) You should immediately contact the relative stating at that place to receive the same on your behalf or ask the postman to put on hold or to redirect the same to your current address.
4) Yes you can do it
5) How can you send a stay order on your own?
6) You can get NOC from him and engage a new lawyer.