Once a case has started and you realise someone important is missing, the best way to fix it is to act fast and treat it as a curable procedural mistake: first, check if that person is really a necessary party by asking, “Can the court pass a complete, effective order without them?”; if not, immediately file an impleadment application under the relevant rule (like Order I Rule 10 CPC), clearly explaining who the person is, why their rights are directly affected, and requesting (i) to add their name in the memo of parties/cause title, (ii) to amend the plaint or written statement and prayer if needed, and (iii) to issue notice so they can file their reply. Good lawyers do this as soon as the omission is noticed, mention honestly why the person was not added earlier, address any limitation concerns, cooperate with the court on serving the new party, and then ensure that once the new party joins, the issues and prayers are adjusted so the final decree binds everyone and cannot later be attacked for non-joinder.
