DT-26 or 206 package) are widely available in various MHz frequencies, including 6 MHz, 12 MHz, and 32 MHz, among others. The 32.768 KHz (kHz, not MHz) version is the most common for high-precision timing applications like real-time clocks. 

You can find a wide selection of these components from electronic component distributors and online marketplaces: 

When purchasing, verify the specific frequency (MHz), load capacitance (e.g., 6 pF, 12.5 pF), and frequency tolerance (e.g., ±10 ppm, ±20 ppm) to ensure compatibility with your circuit design.