Dear Himanshu,
Since you are rendering professional services to your client, even if you render such services by yourself or by hiring anyone the nature of services doesnot change. The Act is very clear that if the services rendered is in nature of professional services, TDS is to be deducted u/s 194J @ 10%. There is no other condition in this regard. The services you are rendering since are professional in nature, TDS on same cannot be deducted u/s 194C. It has to be deducted u/s 194J.
For example, if I were an advocate, even if I render services by hiring other advocates be it full time or be it consultants my clients would deduct TDS @ 10% since for them what is important to consider is what is the nature of services that i am rendering to them. How I render that services to them is irrelevant.
Therefore, your client would deduct TDS @ 10% and since the persons hired are freelancers, the retention fees or consultancy fees payable to them you would have to deduct TDS @ 10%. However if there is an employer employee relationship, than TDS on salary u/s 192 has to be deducted.
Regards
Chintan