Hi,
There are no direct laws dealing with probation on a general basis in India, which is, however, a common practice. The (federal) Industrial Employment (Standing Orders) Act 1946 (which is applicable to workmen), provides for a probationary period of up to three months. Certain states have built in the probation concept indirectly into their local laws, which ranges from three to six months. Ideally, a probation period should not exceed 240 days, as several statutory social welfare laws apply to employees who have worked for such period.
Source : Employment & labour law in India - Lexology