Design is a cool choice! You can take NATA for architecture and design programs, or explore UCEED for industrial design at top institutes. Since you're in PCM, you've also still got JEE Main as an option if you want to keep engineering open.
For design, NATA and JEE Main Paper 2 are the main entrance exams. NATA is specifically for architecture and design programs, while JEE Main Paper 2 also qualifies you for architecture at NITs and IITs. Both are solid options depending on which design field interests you most.