my signature in neet application form is my name is first letter capital letters (only one letter) my Father first letter name capital letter (only one letter) my surname first letter capital then small any problem

Hey aspirant , hope you are doing well.
If NTA found any problem in the signature in application they will send u to correct it in mail.So that you need to do immediately the next day. But as per my knowledge the correction window has been closed so we can guess that they saw no problem with your signature.So you can totally be relaxed.

Just make sure thst signature in your admit card and your attendence sheet match to avoid any problems but in most cases , there aren't any complications faced by a student due to his signature.

Also , just so you know , the signature should always be in runny handwriting and you should practice it as its going to be the official one and you are gonna use it for rest of your life.

I can assure you that you aren't going to face any problem as signature is a signature and it doesn't matter how you do it . Many people in the past have faced the same problem but they were all good in the end.
Here's a tip for you -
You should always make sure to do the same original signature of yours at all times to avoid any confusions.
Here's a link which can help you to get Latest information related to NEET exam
https://medicine.careers360.com/articles/neet-application-form
Hope this helped
Thank you