If your mother is an absolute owner of the proeprty which is intending to sell, she should first have a clear and marketable title o the property by a registered partition deed or at least a mutation records from the revenue department to show that she is the owner of the property now proposed to sell.
She should also provide the copy of the parent document to the prospective buyer.
If there is any TDS then she should agree for it and obtain a certificate from the buyer after TDS to that effect so that she can file ITR accoridnlgy.
For LTCG she should consult a CA who will calculate the same and pay the same accoridnlgy or can file a petition for exemption under the provisions of section 54 of income tax act.
2. Market value is the value of the property sold by you, there is no such thing called land value, it may be the government guidelines value. The sale consideration amount received by her shall be the market value which shall be higher than the guidelines value.
3. The mode of payment shall be by cheque or DD or bank transfer viz. RTGS or any other valid mode of transfer.
4. The details of the cheque or DD or any other mode of payment should be correctly mentioned in the sale deed.
5. For registration she shall be personally present in the registrar's office and the payment receipt shall be given by her to the buyer.
6. Read the 1st answer above..
7. You can ascertain the sale consideration received by her and inform your auditor about it accordingly.
8. No, she need not bother about it.
9. If the property remained unpartitioned and in joint possession then the buyer's request can be acceded but since the properties have been partitioned now, all the three should execute a a separate registered sale deed which will avoid future legal hassle, however there is provision for the three owners selling the property together jointly by a single sale deed also.
10. The details to be entered in the joint sale deed or individual deed shall be the particulars of the buyer and seller, description of properties, the source of title and the previous title holders particulars as well as how the previous owner acquired this property etc.