What is the eligibility to join B.Tech? I have completed Diploma EEE in 2018.

The eligibility says nothing about Diploma. I personally haven't seen anyone join by lateral entry in Chennai's campus. It would be better to call and ask, either from Chennai campus or Vellore campus. You can find their contact information online.

An exam shall be conducted for the same every year which you shall be required to pass. Along with a minimum of 45% marks in diploma. For more details refer https://www.vit.edu.in/admissions/admission-criteria

After completing Diploma, you can try for Lateral Entry in the Vellore campus. You will have to give exam+meeting the criteria to get into thru the lateral entry.

If you have passed Diploma try for the lateral entry test where you will be enrolled in 4th semester. Percentage required is 55% in Diploma. Good Luck.

The eligibility to join btech is that u have to score 60% in your diploma.