Hello TaraPandey1,
The MK61 family is part of NXP’s 15-year Product Longevity Program. Being launched in 2011 this family will remain in the longevity program until July 2026. So it would get a bit short on your desired time window.
You may find more information about this longevity program on the link below:
https://www.nxp.com/products/product-information/product-longevity:PRDCT_LONGEVITY_HM
There are newer K6x microcontrollers, but not in the MAP256 package.
My apologies for the inconvenience.
Regards,
Gustavo