Normally, the model is generated based on some available distributions in JAGS, what if we need the parameters to be sampled from other specific distributions.
Is it possible to create a new distribution in JAGS
Depends on what you need the new distribution for. If you want a new distribution to calculate the likelihood, you could use the zeros or ones trick. If you need a new prior distribution, or something else that JAGS does not already have, you this paper gives a good tutorial if you have the requisite C++ experience.