Which of the following sentences is correct?
1) He is 5 feet 3 tall.
2) He is 5 feet 3 inches tall.
3) He is 5 foot 3 inches tall.
Also, why people say 'He got 6 foot' instead of 'he got 6 feet'?
many thanks
Sentence 3 is the usual form, but 2 is also possible. I would rewrite 1 is "5 feet (or more naturally 'foot') 3".
I don't know when I would say "He got 6 foot". Do you mean "he is 6 foot"?
Note that if we use the measurement as an adjective, only the singular form is acceptable:
Do you have any six-inch nails?
She stood on top of a six-foot wall.