Dear Nandha Gopal,

It seems more than ascidian like a spongia, maybe from subgenus Haliclona Grant, 1836

Best wishes,

I think that may be the Botrylloides genera. In Cape Verde there are very interesting colonies of Botrylloides nigrum. 

Best wishes

I think this could be a botryllid ascidian,  but higher resolution of your picture or microscopical observation would be necessary.   It also looks like some encrusting bryozoans,  but it is hard to tell from this image

Green specimen could be a Didemnid ascidian, but without a detail picture and even a proper dissection it's near impossible to confirm.

Up and left reddish colonies could be Botryllinae, and even up-left could be ascidians, but as before, quite difficult to say without dissection (or very detailed picture)