Target class [App\Http\Controllers\Studentcontroller] does not exist.

Try out:

composer dumpautoload

Do you synchronize the vendor folder with? Or do you do "composer install" on your server ?

If you use "composer install", then show your Controller.

You write student controllers, is the file also called student controller or rather StudentController?

If you wrote "StudentController" in your file name, your class must also be called StudentController.

thank you. I guess my controller name is correct as the project is running perfectly in the localhost.

check the spelling of all paths and class names. They must all use the same letter case.

For instance, is it Studentcontroller or StudentController. They are not the same.

After making any changes to class names or file names be sure to run composer dump

thank you. your solution worked. but it was perfectly working in localhost I don't know why.

Your localhost will be case-insensitive.