Do all other forms of liens, mortgages , etc. get wiped away by the tax sale of real estate in Tennessee ?

Not all, some liens such as IRS or other tax liens are not cleared. Also the buyer has to allow for a redemption period for the past owner to buy back the property.

Normally if there is a mortgage, the mortgage company will not allow it to be sold for taxes, they pay the taxes and then foreclose if it isnot paid.