Section 3 of The Transfer of Property Act, 1882 provides the interpretation clause, wherein the meaning of attestation has been provided. It states-

“attested in relation to an instrument, means and shall be deemed always to have meant attested by two or more witnesses each of whom has seen the excitant sign or affix his mark to the instrument, or has seen some other person sign the instrument in the presence and by the direction of the executant, or has received from the executant the personal acknowledgement of his signature or mark, or of the signature of such other person, and each of whom has signed the instrument in the presence of the executant; but it shall not be necessary that more than one of such witnesses shall have been present at the same time, and no particular form of attestation shall be necessary.”

This definition can be simplified in the sense that, where a deed is being formulated for the purpose of transfer of property, between the transferor and transferee, such a deed should be signed or affixed by two or more witnesses of such parties to the transfer. Moreover, the witnesses should affix their mark in the presence of their respective parties or any executant who has been directed to execute such a deed in their behalf. 

As a result, there are several conditions necessary for an attestation to be considered as valid. These are-

1. There should be two or more witnesses involved for the purpose of attestation;
2. The witnesses should attest only in the presence of the parties to the transfer or any executant being directed by such parties;
3. The witnesses should attest only when they have seen or received the acknowledgement of the parties to the transfer affixing their mark to the deed;
4. The parties should sign all pages of the deed;
5. The witnesses are required to sign only the last page of the deed.

There are various qualifications necessary for any individual to be considered as a valid attester, in order to attest any deed concerning the transfer of any property. These are-

1. The attester should be Sui generis- this means that the attester can be sued or sue in the court of law in case of any breach or violation;
2. The attester should have Animo attestendi- this means that the attester should have the intention to attest the deed of transfer of property. The attester should give his consent to affix his mark on the deed and such intention should not be obtained through any wrong measures.
3. The scribe of the deed, i.e. the person who formulates the deed can be considered as a valid attester in the eyes of the law;
4. The Sub-registrar or the Registrar cannot be considered as a valid attester for any deed during registration;
5. The attester should be a major, according to the terms provided under The Indian Majority Act and should be of a sound mind. This means that the attester should be sure and completely aware about his decision to attest a deed;
6. Any illiterate who decides to be a attester should affix his mark through their left thumb;
7. The parties executing the deed cannot be considered as attesters to the deed.