land measurement

Get resurvey done as per laid down procedure either from Surveyor of Tehsildar or any approved surveyor and get a certificate.  As you have an advocate, hope he will guide you on further remedy.

The law under which the acquisition has been done would have provided for the procedure in such  cases.      the said procedure needs to be adopted. 

You can only get a fair idea for a remedy through forum replies, and ultimately it is your local advocate that takes up the issue and has to file suit for compensation as per actual measurement as per deed or surveyor report.  You can read a hundred books on swimming, but you can not swim with that bookish knowledge.  Guidance of professionals is a must, otherwise, you may get sink.

You may exhaust the remedies from the local SDO to make your claim for the actual land acquired by them and to compensate you as per law for the entire property acquired.

If you do not get a proper reply then you may have to approach high court with a writ petition seeking for resurvey and to provide you relief for the excess land acquired  in terms of compensation.

As far as I am able to ascertain Section 3G (5) provides for arbitration proceedings in such eventuality.

3G. Determination of amount payable as compensation.—

(1) Where any land is acquired under this Act, there shall be paid an amount which shall be determined by an order of the competent authority.

(2) Where the right of user or any right in the nature of an easement on, any land is acquired under this Act, there shall be paid an amount to the owner and any other person whose right of enjoyment in that land has been affected in any manner whatsoever by reason of such acquisition an amount calculated at ten per cent. of the amount determined under sub-section (1), for that land.

(3) Before proceeding to determine the amount under sub-section (1) or sub-section (2), the competent authority shall give a public notice published in two local newspapers, one of which will be in a vernacular language inviting claims from all persons interested in the land to be acquired.

(4) Such notice shall state the particulars of the land and shall require all persons interested in such land to appear in person or by an agent or by a legal practitioner referred to in sub-section (2) of section 3C, before the competent authority, at a time and place and to state the nature of their respective interest in such land.

(5) If the amount determined by the competent authority under sub-section (1) or sub-section (2) is not acceptable to either of the parties, the amount shall, on an application by either of the parties, be determined by the arbitrator to be appointed by the Central Government.

(6) Subject to the provisions of this Act, the provisions of the Arbitration and Conciliation Act, 1996 (26 of 1996) shall apply to every arbitration under this Act.

(7) The competent authority or the arbitrator while determining the amount under sub-section (1) or sub-section (5), as the case may be, shall take into consideration—

(a) the market value of the land on the date of publication of the notification under section 3A;

(b) the damage, if any, sustained by the person interested at the time of taking possession of the land, by reason of the severing of such land from other land;

(c) the damage, if any, sustained by the person interested at the time of taking possession of the land, by reason of the acquisition injuriously affecting his other immovable property in any manner, or his earnings;

(d) if, in consequences of the acquisition of the land, the person interested is compelled to change his residence or place of business, the reasonable expenses, if any, incidental to such change. (Emphasis supplied)