How do I set shipping charges based on weight and add a delivery location like Kerala?

Use the Shipping Zone plugin — Manual shipping charges either one fixed amount per order or each product's own shipping cost, not by weight.

1. Open Shipping Zone from the Plugins menu, click + Add Zone, name it and click Create. Under Regions, click + Add region and choose India → Kerala (add more states or pincodes if you need).
2. Under Shipping methods, click + Add method and set Type to Weight-based (brackets). Click + Add bracket for each band, e.g. 0–1 kg = Rs 80, 1–3 kg = Rs 100.
3. Click Save zone. Shoppers with a Kerala address see this method at checkout.

Note: the storefront cart does not send product weights to this calculation yet, so an order can be priced as 0 kg (your first bracket) — place a test order before relying on it. If one fixed Kerala price is enough, use a Flat rate method instead. You ship the parcels yourself by courier, India Post or local delivery.