This can depend on a number of things. The SIA have a tool on their website which can help with trying indicate whether you may be eligible for an SIA licence:
If your personal licence was revoked because you failed to complete your refresher training or you failed to submit evidence to the Licensing Board within the statutory timescales then as of 6 August 2015 the five year period preventing you from applying for a new person licence had been removed.
This means that you can now apply to the Licensing Board in the area where you reside for a new personal licence. You will have to undergo, and pass the full SCPLH Qualification and submit a copy of this certificate with your application for a new licence. If your licence has been revoked for any other reason, you will still need to wait 5 years.