to stay in a place, to sit, or to be somewhere
"he was cochin on da bus"
means: he was sittin in the bus
A place in India where cochin i.e. chilling, maxing and relaxing, hanging out was invented. Nobody chilled out before it was exported by cochin.
Cochin) is a vibrant city situated on the south-west coast of the Indian peninsula in the breathtakingly scenic and prosperous state of Kerala, hailed as 'God's Own Country'. Its strategic importance over the centuries is underlined by the sobriquet Queen of the Arabian Sea. Informally, Cochin is also referred to as the Gateway to Kerala.