Hi ! First of all you haven't cleared about it why you are not eligible. Now, you can do it after b.tech in civil engineering, if and only if you give gate exam in aeronautical engineering. Now, you haven't also cleared what you b.tech or m.tech or any other degree. So hope you understand and best of luck to you.
Candidates can check B.Tech Cut off for Top IITs & NITs here.
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