Resolution when clauses contain more than 1 complementary literals Let's assume that we have clauses $(l_1 \lor l_2 \lor l_3), (\neg l_1 \lor \neg l_2 \lor l_4), (l_1 \lor l_2 \lor l_5), (\neg l_1 \lor \neg l_2 \lor l_6)$, where both $l_1$ and $l_2$ are complementary literals for the clauses.

If we apply the resolution technique for $l_1$ we'll get clauses

$(l_2 \lor \neg l_2 \lor l_3 \lor l_4)$,
$(l_2 \lor \neg l_2 \lor l_3 \lor l_6)$,
$(l_2 \lor \neg l_2 \lor l_5 \lor l_4)$,
$(l_2 \lor \neg l_2 \lor l_5 \lor l_6)$

How to proceed with $l_2$ from here?
Clauses containing both a variable and its negation are not useful, since they're always correct. You can just ignore them.

Furthermore, you CNF is satisfiable - for example, you can set all variables to TRUE. So it's not completely clear what you are trying to accomplish.