1.i installed a new style called "X-SILVER" and i also installed some mods..they are :-
ACP Announcement Centre
Activity Stats MOD
NV recent topics
ReIMG Image Resizer
but now some mods are visible in prosilver style but not on x-silver..what can i do to get it visible in x-silver
You have to repeat all the template edits in every style you are using.
2.is there a way to enable HTML while posting threads ?
No, and there never will be, for security reasons.
Almost anything you could want to do with HTML can be done with custom bbcodes, which are the safe alternative.