Yes, you can pursue a contested divorce proceeding without coming to India through Video Conferencing or through any relative in India. However, for any important stage of the case like evidence, etc., the concerned judge may insist on physical presence.  

To get a foreign decree invalidated through Indian courts, the party has to prove that the foreign decree obtained has any of the following lacunas:

• Where it has not been pronounced by a Court of competent jurisdiction;
• Where it has not been given on the merits of the case;
• Where it appears on the face of the proceedings to be founded on an incorrect view of international law or a refusal to recognize the law of India in cases in which such law is applicable;
• Where the proceedings in which the judgment was obtained are opposed to natural justice;
• Where it has been obtained by fraud;
• where it sustains a claim founded on a breach of any law in force in India

By default it’s valid but the opposite party can file a case in Indian courts to get that decree invalidated.