As per Indian law - When a document is said to be attested in relation to an instrument when two witnesses each of whom has signed or affix his mark to the instrument, or has seen other person sign the instrument in the present and by direction of the executant of such instrument or has received from the executant personal knowledge 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

It shall not be necessary that more than one of such witness shall be present at the same time and no particular attestation shall be necessary.