My visa is valid until 27 May, My return to Philippines (from Paris) is 30th.
Is this okay to exit schengen state even my visa already expired? still I did not breach the 90/180 rule right?
If your visa is only valid until the 27th of May, you must leave on or before the 27th of May. The 90/180 rule is important, but following that rule doesn't help you if you are ignoring the validity period. You must follow both.
If you delay your departure until the 30th, you will be illegally present in the Schengen area on the 28th-30th. This will lead to a serious and not very enjoyable discussion with the border agents when you leave, and may cause you severe difficulty in the future if you wish to visit the Schengen area again, or if you apply for a visa for any other country which asks about your travel history.
If you entered on a visa that expires on the 27th of May, then the Schengen rule does not apply for a period after the 27th.
For persons who need a visa:
Border code Article 8 (Border checks on persons)
an expired visa is not valid.
The visa handbook, which can be found as link of 'Operational instructions of the visa code... '
explains period of vality inside Chapter 8 as
Although the EU is generally lenient when it comes to people departing the EU after their visa has expired, you are exposing yourself to possible inconvenience. The circumstances why your Visa expired while you are still in the EU may be investigated.
I would not recommended it,anyway renewing your visa only takes a few days. Since you already have a visa you are likely qualified to get an extension