$BTC projects often have their own native tokens (e.g., Decentraland (MANA), The Sandbox (SAND), Axie Infinity (AXS)). You would purchase these specific tokens on cryptocurrency exchanges, not directly on a "Meta planet" unless it's a specific game or platform within the metaverse that offers in-game purchases using its own or widely accepted crypto.

* Metaplanet: This is a Japanese investment company that has been actively acquiring significant amounts of Bitcoin for its treasury. They are a publicly traded company, and their stock price has been influenced by their Bitcoin acquisition strategy. You would buy shares of Metaplanet (a stock) through a traditional stock brokerage, not Bitcoin directly from them. Their strategy is to accumulate Bitcoin as a corporate treasury asset.

To purchase Bitcoin (BTC) generally, you would typically use:

* Centralized Cryptocurrency Exchanges (CEXs): These are platforms like Binance, Coinbase, Kraken, etc., where you can buy Bitcoin directly with fiat currency (like USD, INR, EUR) using various payment methods (bank transfer, credit/debit card). These exchanges act as custodians for your crypto unless you withdraw it to your own personal wallet.

* Decentralized Exchanges (DEXs): These are peer-to-peer trading platforms, but they primarily deal with swapping one cryptocurrency for another (e.g., Ethereum for Wrapped Bitcoin). You would usually need to acquire a base cryptocurrency (like ETH) first from a CEX to then use a DEX.

* Peer-to-Peer (P2P) platforms: These platforms connect buyers and sellers directly, allowing you to exchange fiat for Bitcoin.

If you clarify what you mean by "Meta planet," I can provide more specific guidance. Are you referring to:

* MetaMask wallet?

* Meta Platforms (Facebook's company)?

* A specific metaverse project?

* The company Metaplanet?