Hello aspirant,

Anna university offers admission on the basis of tnea(tamil nadu engineering admission).

The eligibilty of tnea for candidates having done 10 and 12 from outside state are granted admission in special cases when

1)The candidate is a tamil nadu native.These candidates have to show nativity certificate.

2)Candidate whose parents are central government employee and are working in tamil nadu for 5 years.

For more details on eligibility refer the site

https://www.google.com/amp/s/engineering.careers360.com/articles/tnea-eligibility-criteria/amp

Anna university opens admissions through management quota for other state students.Also there  is an all india notification which is passed.The university then on the basis of 12 marks takes admissions of outside state students,but solely depends on availability of seats.

Hope it helps.