Structure related query

I have 500 regions(areas) in our country India, and i was trying to figure it out what will be the most optimal way to store this doc in elasticsearch?

KTYM in TAGS is one of the 500 regions

The reason why i wanna do it because i wanna give different _boost value to same doc in different region.

So which structure will be most ideal ?

one way is to store 500 such docs with different region , but then consider i have 200 * 500 leads to a huge number, so was finding a way to acheive

    "_index": "in",
    "_type": "event",
    "_id": "KTYM-ET",
    "_version": 2,
    "_score": 1,
    "_source": {
    "GRP": "Event",
    "TITLE": "Asia Pacific Boxing Championship",
    "TAGS": [
    "_boost": 11.79,