Nexus between Road Permit in Delhi and C Forms

One of my client in Mumbai has dispatche the goods to Delhi distributor with tax invoice after charging CST 2%.But Road permit was given by the Delhi distributor and also goods has not been caught at any check nakas of delhi and Finally goods were dekivered to Delhi distributor. Whether it is required under Delhi sales tax act to submit the Road permit to get the C Forms? If yes than what is remedy to my client to get C -forms from delhi based distributor.