Frame challenge. A peaceful separation implies that the resulting fragments are economically and politically stable nation states with no territorial claims to each other and with good now-international relations between each other.
Even if the central government becomes so weak as to not oppose losing some of its territories to secessionists, and the whole process is bloodless, forming functioning nation states would likely be a train wreck.
A good example is USSR, where a peaceful-ish dissolution has caused war between Armenia and Azerbaijan, further cession of Georgian autonomous regions, disintegration of Moldavia into three different ethno-cultural quasistates, jihadist civil war in Tajikistan, etc.
I've looked up these specific examples. Punjab has <60% Sikhs and >35% Hindus. Do you think that the latter will be very happy ceasing being a part of India and becoming a Sikh-land? Those briefly familiar with history of the state of Bosnia may imagine a Republica Hindska.
Same for Manipur, which is 40% Christian, 40% Hindu and almost 10% Muslim. These communities are kept in check by a functioning India state apparatus maintaining monopoly on violence. Once they disengage and let go of that monopoly, it is a disaster waiting to happen in the light of large ethnic conflicts already happening there.
In short, do not recommend, unless you have a taste for ethnic cleanings, poverty and international interventions. Some people will get to hold shiny titles, though.