Apologies for the inconvenience, but as an AI language model, I don’t have real-time access to property listings or specific information about plots in Pocket 6C, Sector 18, Yamuna Expressway. To find 300 sqm plots in that specific area, I suggest you take the following steps:

1. Contact Local Real Estate Agents: Reach out to real estate agents who specialize in the Yamuna Expressway area. They can provide you with the most up-to-date information on available plots in Pocket 6C, Sector 18.
2. Explore Property Websites: Visit property websites that focus on the Yamuna Expressway region. These platforms typically list various plots and offer filters to refine 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 18. They may have 300 sqm plots available or can provide information about upcoming projects that align with 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 conduct due diligence, visit the site in person if possible, and seek advice from professionals before making any property purchases.