Dear leaner,

The purpose of neet asks roll number of 12th is for verification of the student that if he/she eligible for exam or not.

According to nta neet form ,before submitting the application the student should fill in online application form such as name,father's mother's name without any spelling mistakes.

And Aadhar card number of the student or

Class 12th roll number which is issued by board if not

You can also enter election card number,or else passport number / ration card number/ bank account number, other any government valid card numbers .

You have these many options to fill the roll number of 12th don't worry , go through this link for ny other information regarding neet .

https://www.google.com/url?sa=t&source=web&rct=j&url=https://ntaneet.nic.in/ntaneet/ShowPdf.aspx%3FType%3D50C9E8D5FC98727B4BBC93CF5D64A68DB647F04F%26ID%3D1B6453892473A467D07372D45EB05ABC2031647A&ved=2ahUKEwiD3NCCmeTxAhUM7XMBHfgVA8IQFjAMegQIGxAC&usg=AOvVaw2Lp7aeRqJ4pbHO5PDzdi1s&cshid=1626321933600 All the best.