The IRS has broad authority when attempting to collect delinquent tax, but there are limitations to what collections actions they can take. The IRS generally has to follow certain procedures before they can levy, or seize, your property, and certain property is exempt from IRS seizure.
Generally, the IRS must send a taxpayer a Notice of Intent to Levy, which gives the taxpayer 30 days to request a Collection Due Process hearing. This gives you a chance to avoid the levy by negotiating an IRS installment agreement, an offer in compromise, or disputing the underlying tax liability, if you have not previously had an opportunity to do so.
The IRS also has a general policy to only seize a taxpayer’s assets as a last resort. If you are attempting to negotiate and cooperate, you should be able to work out an arrangement and prevent your assets from being levied.