Did you miss the registration deadline? Make yourself REACH compliant as soon as possible
ECHA provides information on what to do if you need to register your substance and missed the last registration deadline.
The 31st of May was the last chance to submit a registration for existing (phase-in) substances manufactured or imported in amounts more than one tonne per year. If the registration obligation applied to you but you did not submit your dossier then, as of the 1st of June you can no longer manufacture or import your substance legally in the EU/EEA.
You can find more information on what to do and how to register on the ECHA website