Every Pakistani has the right to purchase property in any part of Pakistan. He is allowed travel to any place, and he can choose to settle down in any city of Pakistan. Article 15 of the Constitution of Pakistan, 1973 gives this right to every citizen of Pakistan.
Every citizen shall have the right to remain in, and, subject to any reasonable restriction imposed by law in the public interest, enter and move freely throughout Pakistan and to reside and settle in any part thereof.
The government can make laws to prohibit or restrict movement in certain places. Similarly, it can make laws to disallow anyone from purchasing property. These restrictions must be reasonable. Reasonable is something which a man of ordinary prudence would find logical and right. For example, you can be restricted from walking into the Army Headquarters, or you can be restricted from going into a park without paying the entry fee. But the government cannot say, for example, that a Punjabi cannot go to Karachi, or that a Baloch cannot buy a property in Punjab; because this is racist and not reasonable at all.
If you find that there is a law, or government action, which violates this fundamental right of yours, you can file a petition in the court to have that law struck out (=cancelled), or to have that action rescinded (=taken back).