hi,

if you already did pass diploma in engineering, you can join b.tech course from second year of studies. however there is some state wise entrance test, by which score the admission in various colleges done, for example,  bihars engineering colleges, BCECE LE (Bihar Combined Entrance Competitive Examination (Lateral Entry) is evaluated. the form will be available on last week of april 2020. for wb jelet entrance test, form will be available on last week of march 2020. you need to appear in lateral entry entrance test if you want to take admission in good colleges.

hope you may understand.