Steps to implead a party in final decree

Mr. X filed money suit againt B B contested case and preliminary decree passed againt B. Now A filed final decree petition. B died without filing counter in the final decree petition. The question is whether to add legal heirs of the deceased defendant in the final decree petition only or to add in the main suit or in both. Further, if steps petition filed, giving notice and copies to otherside advocate is enough or paying bata also necessary. Pls advise Sir. Thanks