Hi @vineet7878
I think SAS releases its software every 6 months. However it doesn't mean it will release the Minor, Major version during that time frame. While M6 was released on Nov 2018, over the time there could be several sub product version release or updates on M6. So to confirm if any recent release has any major changes would really depend on what products are licensed at your site.
If you are looking for an official answer that would help you decide weather to upgrade to M6 or not, I would suggest you to reach out to your account exec. to help you check with this.