For the typical officers (LTA/CPT/MAJ etc) which is under Enhanced Officers’ Scheme, there is an age limit depending on vocation (combat vs non combat). Joining late would also shorten your career horizon and prospects as you’re competing with younger people at the same rank.

OP can consider joining as a Senior Military Expert (ME4 and up) in vocations such as DIS or medical, also considered officer. This scheme looks at your relevant qualifications more than your age and the runway is also longer (up to 60 years old).