No, you are not eligible for your roommate’s insurance policy if your name is not listed. You need to buy your own policy or ask your roommate to add your name on their renters insurance policy for you to be covered.
The information in this answer is general in nature and is not legal or insurance advice for your specific situation. Policy language varies carrier by carrier; your declarations page is the final word. If you're unsure, call your agent before you need to file.