Hi Padmavathi,
Looks like you haven't yet completed 50 posts. Check for the post count shown on the top right corner of your post and you will see the valid total post count.
For your info - posts made in forums like Forward Messages & Jokes, Games, Wishes and IL'ite milestones do not count towards total post count (refer
this announcement). Though the posts are allowed to be in the forums for the pleasure of participating in the community.
Keep participating by making quality posts for the community and you will soon get all privileges like PM.