We are expecting a notification from COA in few days... You can also refer www.nata.in for the same
There are no changes in NATA exam except that it is getting conducted twice this year.
Yeah. You get your rank based on an average of your boards and nata score. So try and get maximum in both areas to get a good rank.
no that's incorrect, you just have to qualify 12th / be 12th pass to give the exam.
for more info check this out