It is not necessary to use high-octane petrol to run the car. you may run the car on normal petrol also. However, it delivers better power performance with high-octane petrol.
There is only one variant in Nissan GTR and i.e 3.8 V6. It is priced at Rs. 2.12 Cr (Ex-Showroom Thiruvananthapuram). In order to know the approx on-road price click on the link.