Lorry services by way of commission /agent basis

Hi,

Iam a transport commission agent. I arrange vehicles from sub brokers or lorry owners attached to me and supply the vehicles to transporters (GTA).

The transporter pays me the freight agreed. I inturn make the payment to sub broker or lorry owner against a cut or commission.

Let's say I hired a vehicle for 25000/- from a sub broker / lorry owner and supply to a GTA for 27000/-. The transporter pays me  and I pay the sub broker / Lorry owner.

So I earn 2000/- which is my commission income.My query is will the 27000/- amount be considered my turnover or not.

it attract gst if attract how much % we charge