Quote:./hc -m 11300 -a 3 --increment --increment-min 12 --increment-max 13 litecoin.hash ?a?a?a?a?a?a?a?a?a?a?a?a?a
You missed an ?a if you're wanting to do increments. Otherwise, running what you have there should give you a good indication of how long a bruteforce attack of that margin is going to take (I'm guessing 50000+ years?).
You can diminish the workload by adding in your digits in direct locations but still have 6+ characters to bruteforce is still a near impossible task for a slow hash like litecoin wallets.
Code:
./hc -m 11300 -a 3 -w 4 litecoin.hash 32?a?a47?a?a51?a?a
This will give you an idea of what kind of time frame you're working with, for a single 1070 it'll take me 5 years.