Many factual aspects needs to be considered before answering the query raised, in my view.
But, allow me to share "broad" contours about my line of thinking w.r.t. subject matter:
If agreement is for pure 'Supply of Manpower Services' where you have not taken & need not be take any labor-law related registrations (or any other registration mandatory under law) in state of Telangana for undertaking subject work, then, you need not take a gst registration under GST at Telangana.
However, if agreement is for 'Fabrications and Erections Services' (and manpower deployed at Telengana site, are working under supervision & control of supplier) and nature of services required the supplier to be physically present at Telangana (say, being directed related to an immovable property), then, you need to take a gst registration under GST at Telangana. This registration will be either 'Casual Taxable Person' or regular registration (depending upon whether you have 'fixed place of business' at Telangana or not).
These are my personal views and same should not be construed as professional advice.