which type of algae live in deep oceans ??? if it is of red algar type then what makes it live in deep rather than all green algar and brown algae??

Red algae live in deep oceans. This is because red light is easily filtered out by the water as compared to green and brown light which penetrate most deeply. As they reflect red light but absorb green and brown light to get energy, so they can survive even when little bit of light penetrates to the bottom.