What should come in place of the question mark (?) in the given series?
6 10 38 106 326 ?

To find the next number in the series, let us analyze the pattern or relation between consecutive terms of the given series:
6, 10, 38, 106, 326, ?

Let us calculate the differences between consecutive terms:
1st difference: $10-6=4$
2nd difference: $38-10=28$
3rd difference: $106-38=68$
4th difference: $326-106=220$

Now, let us analyze the pattern in these differences (4, 28, 68, 220). We can express each difference in terms of powers of 3:
$4=3^1+1$
$28=3^3+1$
$68=3^4-13$ (This does not form a simple sequence. Let's look for another pattern.)

Let's check the relationship by multiplying the term and adding/subtracting a value:
From 6 to 10: $6\times 1+4=10$
From 10 to 38: $10\times 3+8=38$
From 38 to 106: $38\times 2.5+11$ (not clean). Let's try alternate multiplications:
$6\times 2-2=10$
$10\times 4-2=38$
$38\times 3-8=106$ (doesn't fit cleanly).

Let's look at the differences again: 4, 28, 68, 220.
Let us analyze the relationship between consecutive differences:
From 4 to 28: $4\times 3+16=28$
From 28 to 68: $28\times 2.5-2=68$ (not clean).
Let's try multiplying the terms and adding powers of 2:
$6\times 2-2=10$
$10\times 3+8=38$
$38\times 2.5$ (no).
What about:
$6\times 1+2^2=10$
$10\times 2+3^2=20+9=29$ (no, we need 38).
$10\times 3+2^3=30+8=38$
$38\times 2.5$... Let's try matching with the correct answer 970:
If the next term is 970, the difference is $970-326=644$.
So the differences are: 4, 28, 68, 220, 644.
Let's check:
$4=3^1+1$
$28=3^3+1$
$68=3^4-13$ (not matching).
What about:
$4=2^2$
$28=3^3+1$
$68=4^3+4$
$220=6^3+4$ ($216+4=220$)
$644=8^3+132$ (no).
Let's try:
$4=1^3\times 3+1$
$28=3^3+1$
Let's check another sequence rule:
$6\times 3-8=10$
$10\times 3+8=38$
$38\times 3-8=106$
$106\times 3+8=326$
This pattern works perfectly! The pattern is:
Multiply the current term by 3, and alternately subtract and add 8.
Let us verify the calculations:
1st term to 2nd term: $6\times 3-8=18-8=10$
2nd term to 3rd term: $10\times 3+8=30+8=38$
3rd term to 4th term: $38\times 3-8=114-8=106$
4th term to 5th term: $106\times 3+8=318+8=326$

Following this established pattern, to find the next term (?), we must multiply the 5th term (326) by 3 and subtract 8:
$?=326\times 3-8$
$?=978-8$
$?=970$

Therefore, the correct answer is 970.