Don't want to appear too rude on your first post but if you typed the same question into google you would get the answer from the revenue website.
€1270 is you annual allowance for Capital Gains Tax - so you can sell whatever you like and the cumulative gain above that is taxable. You can sell them whenever you like - the only thing that differs is the date you need to have paid the tax by: revenue link here
Just make sure that when you say shares, you mean shares, and not ETFs.
There is no tax free allowance for selling shares.
There is an annual Personal Exemption of € 1,270 which is deducted from the gains made by selling shares (and other assets) before calculating the taxable gain and the tax due