The burden of showing the stipulations and terms of the contract and that the minds were in consensus lies on the plaintiff. If the stipulations and terms are uncertain, and the parties are not ad idem, there can be no specific performance, for there was no contract at all.
Supreme Court in the case namely Mayawanti vs. Kaushalya Devi (Civil Appeal No. 4145 of 1984, decided on 06.04.1990) reported as (1990)3SCC 1:  2 SCR 350, dealt with the issue of exercise of Court’s jurisdiction in ordering specific performance of contract.
In a case of specific performance, as observed and followed, the jurisdiction to order specific performance of a contract is based on the existence of a valid and enforceable contract. The Law of Contract is based on the ideal of freedom of contract and it provides the limiting principles within which the parties are free to make their own contracts. Where a valid and enforceable contract has not been made, the court will not make a contract for them. Specific performance will not be ordered if the contract itself suffers from some defect which makes the contract invalid or unenforceable.
The discretion of the court will be there even though the contract is otherwise valid and enforceable and it can pass a decree of specific performance even before there has been any breach of the contract. It is, therefore, necessary first to see whether there has been a valid and enforceable contract and then to see the nature and obligation arising out of it. The contract being the foundation of the obligation the order of specific performance is to enforce that obligation.
Court further elaborated by observing that it is settled law that if a contract is to be made, the intention of the offeree to accept the offer must be expressed without leaving room for doubt as to the fact of acceptance or to the coincidence of the terms of acceptance with those of the offer. The rule is that the acceptance must be absolute, and must correspond with the terms of the offer. If the two minds were not in consensus in respect of the subject (property to be sold), there cannot be said to have been a contract for specific performance. Where parties themselves are not in sync as to the subject matter of the contract the court cannot order specific performance.
When a promise is made in an alternative form and one alternative is impossible to perform, the question whether the promisor is bound to perform the other or is altogether excused depends on the intention of the parties to be ascertained from the nature and terms of the contract and the circumstances of the particular case. The usual result in such a case will be that the promisor must perform the alternative which remains possible; but it may be that on the proper construction of the contract there is not one obligation to be performed in alternative ways but one obligation to be performed in one way unless the promisor chooses to substitute another way, in which case, the primary obligation being impeded, the promisor is not bound to exercise the option for the benefit of the other party.
The specific performance of a contract is the actual execution of the contract according to its stipulations and terms, and the courts direct the party in default to do the very thing which he contracted to do. The stipulations and terms of the contract have, therefore, to be certain and the parties must have been consensus. The burden of showing the stipulations and terms of the contract and that the minds were in consensus lies on the plaintiff. If the stipulations and terms are uncertain, and the parties are not ad idem, there can be no specific performance, for there was no contract at all. Where there are negotiations, the court has to determine at what point, if at all, the parties have reached agreement. Negotiations thereafter would also be material if the agreement is rescinded.