What do you mean by internship? What is the duration of internship?
The above questions are asked by me since you promise the interns the employment on completion of internship.
Internship is a part of academic curriculam stands on a footing different from trainees appointed under standing orders or apprentices appointed under the Apprentices Act. Therefore, there is no employee-employer relationship between you and the interns.
But from your query what I smell is that the internship you have is not a part of academic curriculam and therefore, there exist an employee-employer relationship between you and the interns.
Under the circumstances you need to follow all applicable employment / labour laws from beginning of Internship.
Employment of any person is subjected to the Standing Orders Act or as per your policy if Standing Orders Act is not applicable to you.
You need to understand that training and employment are two different aspect. Person under Internship/training is Trainee and person engaged in job is an employee.
It all depend upon the employer, if considers the employment period from the date of internship or otherwise on the date he confirmed for an employment.
No one is eligible for any sort of leave while on probation or training or internship. There is no specific rule but establishments make provision in their Standing Order. The terms adopted in SO is the rule to follow, hope this will clarify your doubts.
With due respect to you, I would like to differ with you on your statement - No one is eligible for any sort of leave while on probation or training or internship.
Internship is not an employment as I said in my earlier post. Any kind of leave to interns is totally depends upon the arrangement between the interns, the college or the institute of which the interns is a student & the company.
As regards to probationer or trainee, they are the employees of the company and they are governed by S.O. / Law relating to service conditions such as FA, S&E Act as applicable / service rules or policy formulated by the company in accordance with law. The privilege leave is earned by an employee from his day one of employment however he is permitted avail it as per company rules & regulations, generally in next year. Even casual leave is credited in the account of employee from his first day of employment onwards, generally. No Act says that an employee is not eligible to any kind of leave during probation or trainee period, to my knowledge.