Are these sentences correct ?

Question

1.Titanic, which is a huge blockbuster movie, is one of my top most favourite movies. 

2. My sister that has long hair is a teacher in a school.

Answer 1

Not quite.

1) Titanic, a huge blockbuster movie, is one of my favourites.

The 'which is' is unnecessary.  Also, 'top' and 'most' are equally pointless.

2) My sister, who is a school teacher, has long hair.

People are never 'that' - they're always 'who'.  It would be more appropriate to mention her career before her appearance.

Answer 2

1 - has a problem with the adjectives at the end. It's repetitive

-- "top" means very nearly the same thing as "most favourite"

and IF you really want to use both (it's OK if you do), there needs to be a comma separating them.

- Titanic, which is a huge blockbuster movie, is one of my top, most favourite movies.

2 - is grammatically correct but is a LITTLE awkwardly worded. I would say: it should NOT be marked wrong or lose you any points. However, some less-awkward alternatives:

- My long-haired sister is...

- My sister with the long hair is...