Hello Rudranee,

Since you have given NATA & you have more than 50% in your 12th boards, so you are eligible to apply for B.Arch course. With your NATA score , you may get a good college for B.Arch course. Below I have listed the name of colleges where you can apply for B.Arch course in Karnataka through COMEDK - 

• Ramaiah Institute of Technology
• BMS College of Engineering
• PES University
• Dayananda Sagar College of Engineering 
• Siddaganga Institute fo Technology
• Reva University
• KLE Technological University
• Dayananda Sagar Academy of Technology and Management
• The Oxford College of Engineering
• KLS Gogte Institute of Technology
• RV School of Architecture

You can also go through this link and checkout the whole list of private colleges in Karnataka offering B.Arch courses : https://engineering.careers360.com/colleges/list-of-engineering-colleges-in-India?f%5B0%5D=sm_college_degree%3AB.Arch&f%5B1%5D=im_field_ownership%3A967&f%5B2%5D=sm_college_state%3AKarnataka&f%5B3%5D=sm_quali_exam%3ACOMEDK%20UGET&f%5B4%5D=sm_quali_exam%3ANATA

Good Luck !!!