I have my own reservations and doubts to express on the matter. I request you to please review my observations and clarifications on the matter below.
Converting Employees to Contractual Roles
You wish to convert some of your employees into contract, retainership, and consultancy roles so that you can deprive them of the benefits of social securities such as EPF, ESI, Gratuity, etc. If it is permitted, then many employers like you will do it since they want to make a profit at the cost of the social security of their human assets. (There is no issue if some employees want to save some money. I have strong reasoning/logic and, moreover, legality.)
Please bear in mind, whether you employ any person on a contractual basis or through a contractor agency, all labor laws are applicable to them. (I do not agree with this point as it is very much possible in the case of a direct contract with an individual. You only need to have those contracts as professionals and for a certain time period, and thereafter, it can be renewed.)
Retainers and Consultants
Now, on the question of retainers and consultants, you cannot have every class of people as retainers and consultants. Even if you have retainers and consultants, and the employee-employer relationship is established there, your very purpose of doing this exercise is defeated. (No, I do not agree with this. If we do the contract with the consultant/professionals stating a specific task within the stipulated time frame and a certain amount for that period is fixed, nevertheless the amount we are realizing on a monthly basis, then the relationship cannot be established as master and servant. Only ensure that the individuals are raising the invoice with ST, and the company is realizing the payment by deducting TDS.)
So, be careful while suggesting anything to the employer or be careful if your employer wishes to take such steps and you are there as an HR professional.
More discussions on such issues by members are expected in such forums. (Hereby, it is advised to you to please do some more R&D, then we can have some fruitful discussion on this and reach any conclusion.)
Regards.