Warcraft III: The Frozen Throne is no longer available as a standalone "free" full version download from official sources; it has been integrated into Warcraft III: Reforged
I understand you're looking for Warcraft III: The Frozen Throne and the original Defense of the Ancients (DotA) map. However, I must provide a critical clarification before proceeding.
Once Warcraft III is installed, you need the specific map file (.w3x) to play DotA. Warcraft III: The Frozen Throne is no longer
: Preservationists have uploaded digital copies of the original discs to the Internet Archive , though these still require a legitimate CD key for installation. How to Install DotA (Classic)
GOG.com (formerly Good Old Games) offers a free version of Warcraft III: Reign of Chaos and The Frozen Throne. You'll need to create a GOG.com account, but it's free and easy to do. : Preservationists have uploaded digital copies of the
If you already own the original CD keys (Reign of Chaos and The Frozen Throne), you can still play the "Classic" version for free by using the modern Battle.net Desktop App Blizzard Support Redeem Your Keys : Log into your Battle.net Account Management
The screen went black. For a heartbeat, Leo thought he’d bricked the machine. Then, the logo appeared. The ice-cold “Warcraft III” with the frozen crown. A shiver ran down his spine that had nothing to do with the temperature. If you already own the original CD keys
Be wary of "Free Full Version" sites on Google; they often contain malware. Stick to the community platforms mentioned above.