Can I apply for NSEB and kvpy by Aakash institute because my school do not help me to apply?

Dear Nitin, there have been instances where candidates have applied for NSEB independently because their respective schools havent been supportive. You can do the same. However you need to call up the IAPT to confirm the same and you can use this link to contact them: https://www.iapt.org.in/index.php/contact-us-page.html. The IAPY will help you with a centre from where you can proceed further. Regarding KVPY, you can go with Aakash.