What is the total number of matches played in the tournament?

From the given conditions we can form the table as follows:
From the table we can conclude that Karnataka and Punjab have 1 match to play against each other. It is also given that A win can fetch 2 points, and a loss, 0 point.
The maximum points that Gujrat (with lowest point) = 18 + ( 5 × 2 ) = 28 and he may not be eliminated, Similarly there are certain conditions exist where every team has a chance to survive.

2 teams won 2 matches each

C and E won 2 matches.

From the table E won against C and G

From the table G lost 4 matches.

From the given information we can complete the following table it is clear that if a team wins 5 games, then also there is no guarantee of its advancement to the next stage, since only 4 teams can go to the next stage.
Note: In the table W ? Wins, L ? Loose, × ? No match (as example there can not be match between 1& and 1, 2 and 2 and so on)
The above is one of such combination. Since after winning 5 matches too, there is no guarantee to advancement, so the answer must be 6, because no two teams can get 7 points each.

In stage I, in a group in total 6 matches and that will have 12 points in total.
Total number of matches in this stage is 4 × 6 = 24
In stage II, total 8 players and they play each other except a player who comes from same group but point of their match in stage I is carried forward hence in stage II total points is 28 × 2 = 56.
Number of matches in stage II is 7 × ( 8/2 ) ? 4 = 24
In stage 2 total points are 56.
Consider bottom 3 players, they must play three matches among themselves and hence they have minimum 6 points with them,
Remaining points 56 - 6 = 50 if equally divided between top 5 then one would get 10 points, so to guarantee a seat in semifinal Ricky Singh has to score 12 points .

In stage I, in a group in total 6 matches and that will have 12 points in total.
Total number of matches in this stage is 4 × 6 = 24
In stage II, total 8 players and they play each other except a player who comes from same group but point of their match in stage I is carried forward hence in stage II total points is 28 × 2 = 56.
Number of matches in stage II is 7 × ( 8/2 ) ? 4 = 24
In this case we have to minimize the points scored by 4th ranker (Who advanced to Semi Final). In order to minimize the points scored by Ricky Singh top three players should get maximum points, Let points achieved by top three player at the end of stage II is 14, 12 and 10 summing up to 14 + 12 + 10 = 36 and remaining points 56 - 36 = 20 got distributed to bottom 5 players.
To minimize the points scored by Ricky Singh, all of the bottom five got same point (20/5 = 4 points) and with complex tie breaker Ricky is advanced to Semifinal.

In stage I, in a group in total 6 matches and that will have 12 points in total.
Total number of matches in this stage is 4 × 6 = 24
In stage II, total 8 players and they play each other except a player who comes from same group but point of their match in stage I is carried forward hence in stage II total points is 28 × 2 = 56.
Number of matches in stage II is 7 × ( 8/2 ) ? 4 = 24
In stage 1 a player has to win minimum 1 match to advance to the next stage.
Now consider the different groups,
South Kolkata : 1, 8, 9, 16 [seed 9 can advance after beating seed 16 without an upset]
North Kolkata : 2, 7, 10, 15 [seed 10 can advance after beating seed 15 without an upset]
Central Kolkata : 3, 6, 11, 14 [seed 11 can advance after beating seed 14 without an upset]
Saltlake : 4, 5, 12,13 [seed 12 can advance after beating seed 113 without an upset] So seed 12 is the lowest seed who can advance to stage II without causing Upset in stage I, and can win the tournament [Please note here that in stage II or semifinal there may be an Upset

In stage I, in a group in total 6 matches and that will have 12 points in total.
Total number of matches in this stage is 4 × 6 = 24
In stage II, total 8 players and they play each other except a player who comes from same group but point of their match in stage I is carried forward hence in stage II total points is 28 × 2 = 56.
Number of matches in stage II is 7 × ( 8/2 ) ? 4 = 24
Total number of matches are as follows
Stage I: 24
Stage II: 24
Semifinal: 2
For 3rd place (Looser of semi final): 1
Final: 1
Total number of matches is 52 and hence total number of points is 52 × 2 = 104