Apprentices are engaged by following Apprentice Act 1961. In order to engage apprentices you have to register under the Apprentice portal of government of India. There are two types of apprentices, viz, Designated Trade apprentices and Optional Trade Apprentices. For more details visit the official website https://www.apprenticeshipindia.gov.in/
If you do not wish to have apprentices but would like to employ freshers as trainees, then you need not register under the above said portal but you can take trainees in various departments. But the trainees are employees for all purposes under the labour law, and as such they should not be deprived of any right conferred to a worker under the law. As such, trainees should be given minimum wages prescribed by the government, they should be given ESI/ EPF subject to their salary, they should be given bonus, leave with wages and their training period should be considered for calculating their gratuity at the time of their discharge. Very simple, hiring employees as trainees should not be looked as a part of reducing the burden of the employer.