GST on share of profit

We are toll collecting agency and take govt. contracts time to time as per tender raised by NHAI.
Now, we have taken one toll plaza in JV with one another toll collecting agency but the agreement is not registered or Notarize for the same contract. The installation payment to NHAI and also the toll collection will be done by that another toll collecting agency not by us.
We just paid 50% of performance security as per agreement.
now that another company also wanted to give us share of profit.

my question is whether that share of profit will be applicable for GST and if yes what will be the rate ? and if no, that then plz provide us with some order or case law passed by concerned department or honorable court with regards to same case ?