Citiation over dismissal of suit for non joinder of parties

You need to state the facts of the suit .however  it is settled law that a decree does not bind the stranger who is not made the partty to the suit . if the staus  of the party who is not joined, is such that he can  object and frustate  the decree by objecting to its executability  against him,   he is a necessry party , whether a particular party is a necessary party or not will depend upon facts of eah individual case 

thanks pandey ji,

The case is I am a BSNL employee undergone treatement in Hospital which is empanneled to BSNL made an Agreement with BSnL and agreed to submit the bills of BSnL employees/dependents and will claim as per CGHS rates.  Claimed bills to BSnL, BSNL did not paid part of the bills, so on instigation from some people Hospital filled a suit (case) in the court without making BSNL a party stating that I have to pay the remaining bills, where as, as per the agreement BSNL had paid appropriate bills to Hospital.  Hospital is agreeing that he has submitted the bills to BSNL which is under process.  Without making BSNL a party how Hospital can file a suit on employee.  Whether the suit is tenable, we have argued to court to dismiss the case because of non joinder of necessary party.    I wanted any such citiation over dismissal of suit for non joindner of parties when they made agreement like this and Arbitration and councilation act 1966 is there, in case of disputes an arbitrator appointed by BSNL will take a final decision.  As Hospital did not made BSNL a party (to keep his relation smooth with BSnL) and filled a suit against us.

Hence citiation is needed.. please help.