Saffronisation is the process of advancing the Hindutva project in ways which last beyond the lifetime of a particular goverment. These include:

Filling institutions with RSS cadre or sympathisers;
Interfering in or even dissolving institutions deemed antagonistic to the Hindutva project;
• Creating new institutions and posts (such as a ministry for cows in Rajasthan);
Bringing the RSS into decision making at all levels; allowing or encouraging civil servants to join the RSS.
Altering educational curricula and practices, with an emphasis on creating versions of history which fit the Hindutva narrative;
• Normalisation of the use of Hindu rituals in the public sphere.
• Forcing all students to perform Hindu religious rituals;
• Interfering in cultural and media activity via promotion of Hindutva material and censorship of other material;
Increased interference and tightened control over state-controlled media.
Introducing a religious/ideological component into various state/NGO activities;
• Honouring Hindutva icons in symbolic but lasting ways.

References: Many examples beyond those linked above can be found in articles tagged saffronisation on Narendra Modi Facts.