No they’re not the same thing. Rotel is basically tomatoes and chilies which can be used to make salsa.
Salsa is typically referring to a condiment made with tomatoes, onions and chilies. But as consumer demand for salsa escalates, the literal translation becomes more applicable. Sauces abound. Some contain ingredients not typically associated with salsa: papaya, mango, plantains and corn.
Here's a restaurant style salsa using canned tomatoes, Rotel (tomatoes and chilies), onion, fresh jalapeno, salt, sugar, garlic, and cilantro shared by Thepioneerwoman.com.