If I rolled over pre-tax 401K money to an IRA, do I have to report this amount on line 6 of form 8606? Previously the 401K money was excludable. Should still be excluded.

Yes, any money the IRA owner's traditional IRAs at year end must be included on Form 8606 line 6.  No, it cannot be excluded from line 6.

It's a relatively common mistake for individuals trying to execute a nontaxable "backdoor Roth" that the individual rolls money pre-tax over from a traditional 401(k) to an IRA, causing the Roth conversion that is part of the backdoor procedure to be largely taxable instead of tax-free and causing a large amount of the IRA owner's basis in nondeductible contributions to remain in the traditional IRA to be applied proportionately to future traditional IRA distributions.