Part Time B.Tech

I guess it's applicable.

AICTE approved part time B.Tech colleges in Kerala and Tamil Nadu are:
Anna University,
Sathyabama University,
VELS institute of science and technology,
Bharath University,
Madras Institute of technology,
SRM institute of technology.

IEC University of Engineering in Bikaner is offering B.Tech for part time only but not in evening.
If you want to do in evening you can join distance course that are available in colleges in Bikaner.

B.Tech and BCA both are different fields so you will not eligible for take lateral entry in B.Tech. If you wanted to be an engineer. You most to pass 12th exam with math stream and to be appear in JEE Mains exam then you will be eligible for B.Tech course. B.Tech and BCA are different field of study if you wanted to take lateral entry then you most to pass Diploma then you will eligible for lateral entry in B.Tech.

You can go for Chandigarh university, CU will give you lot of exposure, syllabus focuses more on practical knowledge. Asian Paints has selected 7 Diploma Engineering students of Mechanical branch from Chandigarh University during a campus placement drive. The multi-national has picked up many students during in two years. CU also focuses on extracurricular activities participating in various activities helps students to be more confident.

If you want professional course to pursue, here is the list of some courses which may help you in future. -
-Job Oriented skills course
-Language course
-Personality development course
-Computer Application course
-Management course etc.

Yes, Diploma students can appear for these exams.

Hi Pankaj, You can definitely do without any hesitation, but I prefer to do in full time mode, so that it can help you more.