You have to prove the will by evidence of attesting witness who were present at time of execution of will
2)
Section 71 of the Indian Evidence Act is to meet the situation, where it is not possible to prove the execution of a Will by calling the attesting witness, though alive, or when the attesting witnesses have been called, they deny or fail to recollect the execution of the document. In that way, Section 71 of the Indian Evidence Act is incorporated to safeguard the mandatory provisions of Section 68 of the Indian Evidence Act. Section 71 of the Indian Evidence Act is only to give assistance and come to rescue of a party who has taken steps to get attesting witness to give evidence, but he failed to such witness denied or failed to recollect the execution of the Will. This is only with a view to prove the due execution by "other evidence"...."
4)AIR 2008 SC 2485 (Babu Singh and others V. Ram Sahai @ Ramsingh) wherein the Supreme Court has held as follows:
"14.It would apply, inter alia, in a case where the attesting witness is either dead or out of the jurisdiction of the court or kept out of the way by the adverse party or cannot be traced despite diligent search. Only in that event, the Will may be proved in the manner indicated in Section 69, i.e.,by examining witnesses who were able to prove the handwriting of the testator or executant.