If you belong to Hindu Community, you cannot marry two girls legally. The same thing holds good for the the Christians. However, being a Muslim, they have the privilege of marrying as many girls as they want since their religion does not have any objection in this regard.
However, in some exceptional circumstances, a man can contract marriage with another girl in the Hindu Community despite having a wife in some exceptional circumstances. This could be due to her inability to conceive and from the side of the husband and his close relatives, there is a pressure for a fresh marriage of the husband with some girl, the marriage can be negotiated with the consent of his first wife. The same has to be approved from the court even,
However, being a Hindu or a Christian and are on the job in a government service or a public undertaking, an employee should have a single wife and in case of noncompliance of the same, one is liable to be punished.