i am fail in 12 science. so please tell me what can i do?

completr the 12th than think for further education. you may opt polutechnic diploma on the basis of your 10th

Do n't worry .You can do Polytech on 10th certificate . it is also a better option or you can do your 12th firstly then think about doing bsce or b tech next year.

First clear your subjects what you have failed.Then think about future course.If at all it is not possible to clear the course means,better to join Diploma( polytechnic).It is easy for you to crack the course,because you already in science stream.