If I fail my 11th class what I will do next?

Can you repeat the grade? Correspondence and online courses are also available so research on those options. I strongly suggest you finish high/secondary school before looking for full time work.

Summer courses... I never failed a grade but it sucks to repeat a grade because of language barriers. That is what I had to do since I was raised in a foreign country during the time I was suppose to learn my ABC's and I learned their foreign language instead. I was suggest talking to your school counselor about your grades and see if you can withdraw from some of your classes without failing. It is the only way to keep your gpa up and do summer courses if they offer it. Or you can drop out and transfer to an adult education center and receive your high school diploma from there in on semester.