whether a lawyer can ?

I assume the lawyer-client relationship is supposed to possess that kind of understanding, in as much as the client is not worried about his own advocate's intentions. Hopefully, your advocate hasn't been paid/bought by the other party to the case.

if the same was recovered by police, whether the advocate will become a accused for that case ?

No, an advocate will not be liable for his client's actions. There's a thing called attorney-client privelege which has been covered under sections 126-129 of the Indian Evidence Act. In short, anything disclosed by a person to his advocate cannot be revealed by that advocate, even if it discloses the person's criminal guilt, so long as the activity discovered is not in furtherance of a crime, or has not been committed by the client after the commencement of his contract with his advocate.

Yes, the lawyer can based on the mutual understanding.