If you wish to contest a will, you must start court proceedings within the limitation period. If you do not, you will be time-barred from bringing any claim and your right to contest the will will be lost.
There are some exceptions to the limitation period. For example, if the person contesting the will is under a disability, such as age or mental incapacity, the limitation period may be extended. It is always best to seek legal advice as soon as possible if you are considering contesting a will.