Even in good shape it can be hard to decipher the king's name. Many dealers just call him "octopus man". Here is a high grade example for comparison. Sri Lanka, Polonnaruva, Sahasa Malla, 1200-2 AD, AE20, 4.17g Seated king, SRIMA SAHASA MALLA in Brahmi in two vertical lines in the left field King standing, small altar in the left field, various dots and decorations in fields. 'Octopus Man' Mitchiner NIS 837-839. You can see examples of the various kings at https://www.zeno.ru/showgallery.php?cat=4402 maybe you will find one similar to yours.
I'm no student of these but don't see the legends here. I might have guessed Rajaraja Chola or any of the scores of rulers that were related to him. These are not as hard to ID in good condition but many are simply messes. 'Maybe' is the operative word here.
I got one of these just to "get one of these" octopus man. Bhuvanaika Bahu CE 1273-1284 Æ Massa 3.9g 19mm King throne solar symbol altar flame lotus - King reclining sankh-conch Nagari-Sri Bhuvanaika Bahu MNI 851-52 My only other Sri Lanka coin is a bit older: Sri Lanka 1st C BCE PB Lead 1/8th unit Lakshmi excavated in Anuradhapura RARE
I gave IDing the OP coin a shot, but failed, there just isn't much legend to go on there. Here are a couple "octopus king" coins I have. Raja Raja and a queen, Lilivati.
Definitely a Raja Raja Chola coin and not one of the ones from Sri Lanka. Here is a different type of Raja Raja Chola coin with a fish on the right to indicate the subjugation of the Pandyan Kindom, their emblem is the fish: Imperial Chola: Raja Raja I (ca. 1007) AE Kasu (Biddulph-21) Obv: King half seated, with raised arm on right; Devanagari legend beneath raised arm; श्री राजा राजा (Sri Raja Raja) Rev: Standing man, with lamp on left and fish on right, representing the the Pandya conquest
