I saw someones activity like more than 100+ and they got merit like 50 but in this situation what i know is his rank should be at least member rank but why he stack into Jr rank can anyone explain this?
I figure you saw something else and got somewhat confused. My database shows this distribution currently:
rank nAccounts
Legendary 2005
Hero Member 2189
Sr. Member 3844
Full Member 6796
Member 358
All accounts (banned or not) with >= 100 Activity and >= 50 Merits
<...>
The
account you mention has 42 Activity -> Jr. Member still, until he reaches 60 Activity points for Member (having already the required Merits).
See:
https://bitcointalk.org/index.php?topic=2818350.0