Supervisor charges is contract payment or consultancy

It is a contravantional topic, in my opinion

if he is looking aftet the work under the capacity of Engineer and it invloves any professional work then it is 194J

It depends on the qualification of person also

otherwise 194C.

Agree With Sudhakar

better consider it under 194J

Agreed with CA Sudhakar.

If supervision requires professional knowledge the 194J.

On safer side advisable is 194J.

In TDS matters whrn you are in doubt deduct at the higher rate

In Sec. 194J of income Tax 

" professional services " means services rendered by a person in the course of carrying on legal, medical, engineering or architectural profession or the profession of accountancy or technical consultancy or interior decoration or advertising or such other profession as is notified by the Board for the purposes of section 44AA or of this section;

the section strictly referred professional services as highly skilled profession so its on the capacity of person as said by shudhakar will consider to apply section 194J

I also agree with S. Sudarsan.