I apologize, but as an AI language model, I don’t have access to real-time property listings or specific information about plots in Pocket O, Sector 20, Yamuna Expressway. To find 300 sqm plots in that specific area, you can follow these steps:

1. Contact Local Real Estate Agents: Get in touch with real estate agents who specialize in the Yamuna Expressway area, specifically Sector 20. They can provide you with the most up-to-date information on available plots in Pocket O.
2. Explore Property Websites: Visit property websites that focus on the Yamuna Expressway region. These platforms often list various plots and provide filters to narrow down your search based on plot size and other criteria.
3. Consult Real Estate Developers: Check the official websites or contact real estate developers who have ongoing projects in Sector 20. They may have 300 sqm plots available or can provide information about upcoming projects that meet your requirements.
4. Local Newspapers and Classifieds: Browse through local newspapers or classified ads in the area. Sometimes, individual sellers advertise plots for sale directly, and you might find suitable options there.

Remember to exercise due diligence, visit the site in person if possible, and seek advice from professionals before making any property-related decisions.