Hello Aspirant

The difference between both the test are as follows

ANTHE:This exam is an extensive scholarship exam which is conducted at both state and national level.With this exam you are eligible to even get an 100% scholarship.This exam is generally conducted in October for VIII-XII class students

Whereas

AAKASH NEST EXAM:IT is also an scholarship exam that gives a student an opportunity to compete on national level and get a scholarship  upto 90%  on tution fee

NTSE exam detail are as  follow

Eligibility:8-12th student

exam fee:200 INR

Exam date:5th April

timing:11am-1pm &3 pm -5pm

Results on:8Th April

yes you can participate for both exam

Regards!