You need a 6 or 7 with a 63 or 66 at a minimum.Actually in many states it's 6 & 63. I think 6 is the basic one w other states requiring both. & oh yeah. Now they require passing SIE 1st before going on to the others.
But life only licensed agents can work with securities licensed agents/reps who can handle the investment side.
Life only agents can work with those advisors but can't legally be paid on securities or investment advice production.