My friend got Jhalawar Medical College with 500 marks and above in NEET, but with a payment seat through 85% State quota. The basic residence requirement is that you should be a domicile of Rajasthan.
Jhalawar Medical College takes in 100 students each year out of which, 15 are for NRIs, 35 for high tuition fee givers as per Bhargav commission's decision, 15 seats are reserved for All India candidates and the rest are for State quota.
The fee for payment seats is INR 5 LPA, so if you can afford it then go ahead; otherwise, you should target 550+ marks to get admitted to any of the Government Medical Colleges in Rajasthan.
But coming to the preparation, you can prepare by revising NCERT books of Biology, Physics and Chemistry. Don't forget to practice previous year’s papers at home in a timed fashion.