Looks to be some sort of red algae (and some green algae closer to the rock), or possibly some species of hydroid.

It can be a Hydroid, possibly an athecate one, but it's impossible to identify if we can't see a hydrant. There are many species with brown stems.

Dear Rajan,

I think that your specimen is from India, but if you can help me with more details about Its location I could give you a better idea about that specimen.

If you can present some images about the polyps at microscope would be ideal for identification work.

Dear Damian sir,

here I attached specimen microscopic photos.