I dunno, what is a true Indian? But by & large- yeah, the Muslim pop in INd has been quite loyal to the country in its most testing times. If you think today is bad, don't forget 1970s. Muslim Pak viewed the war as India destroying an Islamic Republic in two halves (by breaking East & West Pakistan) and Muslim populations hardly joined Pakistani ranks. 10+ yrs later, when USA & Pak created Talibans in Afghanistan to dislodge the Communist govt there (Kunar campaign- USSR), sizable offers were made to Muslims in India, particularly in J&K, but there were more Yemenis in Talibans ranks in the Kunar than Indians- in fact there was hardly any Indian there. And Pak & US also created false propaganda in Indhira-ji's times that Muslims were being sent to castration camps etc., but Muslims by & large stood by India, if I recall correctly.
True, Muslims in modern post 90s India follow community first, nation second philosophy, but that's true of all religions here