I don't think 'communal' will be the right word to be used here.It kinda refers to different ethnicity.Bangladesh is almost a unicommunal society.But the constitution states that it is a Muslim(not Islamic) country due to majority of its population being adherents being follower of Islam.But it does guarantee(not that its doing a good job in keeping it) the right of all religious minorities to safely practice their faith.
Secularism is not a very well established term.The Soviets were secular and killed Russian Orthodox Christians and Muslims for being religious.USA is secular and I can practice my faith without any intervention from the government level.France is a secular country but England is constitutionaly Christian,its far easier for a Muslim to live in England than it is to live in France.So there is no fixed guideline to become a secular country.It all depends on the culture.India is secular.But from what I understand due to its multicultural society it is more secular in certain parts than it is in others.Kolkata is probably more muslim-friendly than Mumbai.Here's a video: