You may complete certain Diploma Courses in 2/3 years but that wont add value to your profile considering career scope and prospects. You need a minimum 3 years to Graduate either in B.Sc./B.Com/BCA/BA/BHM followed by job opportunities. Try securing a seat in some of the Better Institutes in respective domain for better training and placement facilities. Ideally if you are from Science Background you may pursue B.Sc (Chemistry/Maths/Physics), if Commerce or Arts background B.Com/BA (Economics)/BCA, though their are many new fields like Design,Fashion,Data Science nowadays which are gaining importance among 3 years Courses.

For more information about the List of Courses after 12th do follow the link below

https://school.careers360.com/articles/courses-after-12th