Hello Dek @Sharma,
You cannot go to the regular school at this age, unfortunately.
But if you want to have school certificate, there are other ways called "Zweite Bildungsweg" which means 'Second educational path'. There are preparations courses by educational institutes or Volkshochcschule which you can attend and prepare yourself first for 9th class exam and then other school certificates.
It also depends how long you attended school before.
And if you are a woman, there are also specific projects for women who want to get school certificate at your age. I know some of them in Berlin, if you live in Berlin.
I also saw you had asked about vocational training (Ausbildung) earlier in another post. I will answer there.
If you have more questions about it and you reside in Berlin, you can contact us for an appointment.
Telefon + 49 (0)30 68 05 43 77