Here we have the Concession Agrement signed between BIAL Managment and GOI on 5th July'2004
Artilce 5.2.1 and 5.2.2 of page 22 gives Exclusivity :
Dear Prajagale,
I am sure, all of you must have seen an update from our friend Sanjeev on progress of Suburban Rail project. There is a likelihood that we could hear about the introduction of 1 or 2 services rolled out under this project proposal in next 2-3 months.