Is it possible to increase 7 cm in height after 16 years of age as i am 175 cm right now i want to hit the 6 foot mark?

The limiting factor is the growth plates that support further increase in height. An x-ray of your wrist/hand could detect if your growth plates are open enough to gain that much height. If they are closed you are done. If you have grown 6+ cm in the past year you are likely to grow more. If you grew 3 cm or less in the past year you are almost finished.