As per the news till date, for attempting NATA 2019, you must have PCM as your core subjects.

This question doesn't have any specific answer because in order to take admission to SPA and/or JJ/Rachna Sansad you are awarded a rank based on your marks (in comparison to all applicants). The marks considered here are JEE mains Paper 2 and these marks vary according to the level of competition every year. 

Generally, admissions for architecture at SPA close within top 550 ranks for general category while for Planning it extends up to 2050 ranks.

all subject from your 12th will be considered

it is for 2019 entrance exam.... you can start practice. All the best!

15th of may

The answers you gave during your NATA attempt, essentially are the recorded responses. The final answer key will tentatively be published by third week of May.

According to the NATA brochure, results will be available on the website mentioned. The candidate can access the website with the login credentials created at the time of application.

You can only apply for jee advanced if you qualify for it after writing jee main PAPER 1.