The festivals where everyone would include them selves with out any difference of the religion, place they came from, cast, race etc. are :
1. Holi
2. Ramadan
3. Diwali
4. Easter
5. Christmas

The people celebrate all the above festivals together in unity with out any differences among them. They don't even think of the religion and all they just try to enjoy with the everyone. The people even celebrate the national festivals together like Independence day, Republic day, Gandhi Jayantha etc.