Why Am I getting letter from IRS???

Ignoring the IRS would be a huge mistake. It is hard t say why the IRS thinks you owe income tax, and may be due to an error - or not. However, unless you sort it out with them, they can (nd normally will) file a Federal tax lien against your US real estate, and have the option of selling your house to collect what they think is owedm plus accruing interest and penalties.

If you respod to them and get to the bottom of the problem, you should be able to either resolve it or, if necessary, to pay the tax before matters get far worse.

Unless this house is sitting empty when you are not using it, there likely is an issue of rental income if someone else besides you is living in the house. Alternatively, if the person is living in the house rent-free, there may be issues of gift taxes. Or, if you are paying someone to take care of the house and the person is living in the house, there may be issues of household employee taxes.

If you are a legal permanent resident of the US, your worldwide income is subject to US income taxes.

For whatever reason, right or wrong, you have received a notice from the IRS. If you fail to act on the notice, after a certain time, you lose the right to contest the allegations in the notice.

After following its procedures, the IRS will eventually put a lien on the house. Whenever you dispose of the house, you will have to pay off the lien.

The best thing to do likely is to review the allegations in the notice and see what you need to do to resolve the situation.