For the availability and prices of the spare parts, we'd suggest you to connect with the nearest authorized service center. Click on the link and select your desired city for [service centers@https://www.cardekho.com/Tata/car-service-center.htm
As of now, the brand has not made any official announcement on the price of Hexa but we can expect it to be around Rs.14.00 Lakh (Ex-Showroom). Stay tuned
As you are looking to replace the tyres of your car, we would suggest you get in touch with the authorized service centre of Tata.[Service Centre@https://www.cardekho.com/Tata/New_Delhi/car-service-center.htm