If you get your tubes tied, could you still have a baby with help from ivf?

Absolutely. Blocked tubes is the reason ivf was invented, and ivf is often a better approach than a surgical tubal ligation reversal. See a specialist (reproductive endocrinogy / infertility or rei md) who offers both options to assess your individual situation. Workup includes checking your partner's sperm (semen analysis) even if he's the father of your kids, and checking your egg supply. Best wishes.