Suzuki takes 8 to 10 working days for invoice, if any issues or a cars invoice has to be reissued it can take a little longer.
In any case such a car is not drivable and can challaned for driving a unregistered car.
My cultus took almost 1 month for invoice issuance. But usually it comes under 15 days/2 weeks.
The showroom gave me someone else's car then reinvoiced it on my name. Also offered to take another car and return this car 700 kms driven.