Hello Jamaludheen ,

OBC-NCL , other backward classes- non creamy layer is a Certificate issued by central government to people who are under central OBC list and whose family income is less than 8 lpa.

To apply this certificate for the admission purposes the terms and condition are different for different institutions, but a majority of the premier institution demand a Certificate issued by central government and the Certificate should be dated a year back or 6 months from the date of admission.

A certificate issued by tehsildar can be submitted if the institution allows the certificate from the state government.

If the Certificate is required issued by central government  and you are facing some delay in getting that , then you can submit the certificate issued by tahsildar with a affidavit stating the time after which you'll submit the required Document.

Hope this helps,

Best of luck !