I am thinking of writing the sun solaris system administrator exams but I am afraid.With the sun and oracle thing Will the cert be valid in the next One Year or will It be better if I just go with the LPIC exams.
If you think exams are worth it, the Solaris ones are still going to be worth it irrespective of the outcome of the Oracle/Sun merger. If nothing else, large chunks of finance are already using Solaris and it will take them years, if not decades to move off, even if Oracle decide to EOL Solaris (which they almost certainly won't).
I would go for the LPIC certification first as it is broader and will be of more value to you job-wise. If Oracle should decide to actively develop and/or support Solaris further and the market is in need of Solaris admins and that is still what you really want to do, then you can also go for the Solaris certificate.
But the Linux certificate seems a saner choice to me at this point. Personally I also think that Oracle plans on further developing their Red Hat clone (Unbreakable Linux) instead of choosing Solaris as their main platform.
Anyway, good luck!
If you want to show that you understand Solaris (and, really, demonstrable experience can count far more than certifications, but they do get you past the recruiter/HR-"gate" and LPIC won't do that if you're applying for Solaris roles), then you would be better to study and go with Solaris Systems Administrator I/II and Network Administrator.
I took all three back in the "Solaris 8" era, and found it useful to then be able to discuss the merits and disadvantages of the certifications in interviews. (The most questionable material on the syllabus was the printing sections - I don't think I've ever come across any sites using vanilla Solaris printing software. The most interesting was probably RBAC, which is just now, with Solaris 10, starting to get properly used.)
If, however, you don't have experience and you think that any certification is going to get you past that then don't delude yourself. You need to start as a junior and do your time.