For the availability, we would suggest you walk into the nearest dealership as they will be better people to assist you. You can click on the following link to see the details of the nearest dealership and selecting your city accordingly - Dealers.
As of now the the diesel engine is available for sale but The brand is planning to discontinue its diesel variant after the launch of BS6 engines. But as of now, there is no official confirmation for the same. So stay tuned for further updates.