Yes you can wear both a tulsi mala and a vaijayanti mala together as each has its unique spiritual significance and purpose. The tulsi ki mala in Vrindavan is revered for its connection to Lord Krishna and is believed to purify the mind and soul promoting devotion and peace. On the other hand the vaijayanti mala made of five types of flowers is also associated with Lord Krishna and is considered to bring good fortune and spiritual growth.