The original sentence, “Every of the student have their own laptop,” contains errors in the use of determiners, nouns, and subject–verb agreement.
Each of the students is the correct construction. We use each of, followed by a plural noun.
Each takes a singular verb, so has is correct, not have.
Their can be used as a gender-neutral singular pronoun in modern English.
However, the most natural correction would be: Each of the students has their own laptop.
Why the other options are incorrect:
Every student have — incorrect; every student takes the singular verb has.
Each of the students have — incorrect; each requires a singular verb.
Every of the students — incorrect; every of is not a standard grammatical construction.
