Can i masterbate moderately lifetime from age 16to45,just like 1-2 time a week if not then 2-3 time in month,just normally?i have misbelief that from 16 -19 age we should masterbate regularly but after that we need to stop and do after age 25-26?

Sexual activity whether solo or with a partner is a natural part of life. If done to excess in a way that prevents other normal pursuits/productivity it is a problem. If not, there is no physical or medical reason that requires it to stop. Many cultures promote myths to discourage solo sex. Believe what you choose.

There is no limit or rule about masturbation. Whatever pleases a person is OK.