S1: Our Constitution reminds us of the necessity of representation in a large democracy. S6: Elections have today become the most visible symbol of the democratic process. P: This is why elections become important. Q: Therefore representatives are elected by the people. R: Whenever we think of India as a democracy, our mind invariably turns to our successful elections. S: All citizens cannot participate in taking every decision.

The correct sequence is S-Q-P-R. After S1 mentions the necessity of representation, S explains why representation is needed: 'All citizens cannot participate in taking every decision.' Q follows logically: 'Therefore representatives are elected by the people.' P then concludes: 'This is why elections become important.' R links to S6 by stating that whenever India is thought of as a democracy, our mind turns to elections, leading to S6 about elections being the most visible symbol of democracy.