S1: There is difference between Gandhiji's concept of secularism and that of Nehru's.
P : Nehru's idea of secularism was equal indifference to all religions and bothering about none of them.
Q : According to Gandhiji, all religions are equally true and each scripture is worthy of respect.
R : Such secularism which means the rejection of all religions is contrary to our culture and tradition.
S : In Gandhiji's view, secularism stands for equal respect for all religions.
S6: Instead of doing any good, such secularism can do harm instead of good.
Sentence S1 introduces the idea of the paragraph : difference between Gandhian and Nehruvian secularism. As sentence S1 mentions Gandhian secularism first, the next sentence should introduce what Gandhiji thought about secularism. Sentences S and P both play this role but sentence S is more fundamental in the sense that it tells about the meaning of secularism according to Gandhiji while sentence Q elaborates on this idea. So, SQ form a pair. Similarly, PR form a pair and R is followed logically by S6.
So, the correct sequence is SQPR.