Dear Jijith,
A cross reference from Valmiki Ramayana on location of Bhogavathi
It was in the South in the Indian Ocean. Chapter 4-41 gives the overall picture.
tatra bhogavatii naama sarpaaNaam aalayaH purii || 4-41-36
vishaala rathyaa dur.hdharSaa sarvataH parirakSitaa |
rakSitaa pannagaiH ghoraiH tiiSkNa damSTraiH mahaa viSaiH || 4-41-37
sarpa raajo mahaaghoro yasyaam vasati vaasukiH |
36b, 37, 38a. tatra= there; vishaala rathyaa= with broad, roads; durdharSaa= unvanquishable - city; sarvataH parirakSitaa= everywhere, safeguarded; ghoraiH= deadly; tiiSkNa damSTraiH= with harrowing, fangs; mahaa viSaiH= having fatal, venom; pannagaiH rakSitaa= by [such] serpents, protected; sarpaaNaam aalayaH= for snakes, an abode of; bhogavatii naama purii= Bhogavati, named, city - is there; yasyaam= in which; sarpa raajaH= serpents, king; mahaa ghoraH= highly, hazardous one; vaasukiH vasati = Vasuki, will be dwelling.
"There is a city named Bhogavati which is an abode of the snakes. It has broad roads and safeguarded from everywhere, and thus it becomes an unvanquishable city. Deadly serpents with harrowing fangs and fatal venom will be protecting it, in which the highly hazardous king of serpents, namely Vasuki, will be dwelling. [4-41-36b, 37. 38a]