You have to login in to your account on the official website of the Neet exam by providing your application number and the password. After logging in, you can check the status of your application form. If it successfully submitted, the website will show you the same. 

Hii

You need to log in to your account on the official website and check if you have the confirmation page generated. If the confirmation page has been generated, this means the application has been successfully submitted. Incase it is not accepted you will get an email or a text message for the same.
If you feel like you have made some mistake in your form and worry about the form being rejected, you can use the correction window to make the changes which will be available from 14th january to 31st january.
Once the admit card is released, if you are able to download your admit card then your form is accepted and is you face any issue, then you can mail them your query.

Hope this helps
Thanks!!

Dear Ravi, unlike AIIMS Basic registration, there is no possibility of checking the status of your application with NEET. Once you make a payment, a confirmation page will be generated and this is to be saved for your future references. This confirmation page will also be sent to your registered email id. The generation of this page is proof that your application has been successfully submitted. However, if you need to make any corrections to your application, you can do so during the correction window when it opens from January 14th until January 31st.