I saw four of these posters in the ladies' compartment in a local train in Mumbai four days ago. For those befuddled by my photography skills (combined with an average-at-best cell phone camera), the poster says:
"Never forget 25th June 1975. The day the Emergency was declared. Scrap all repressive laws. Defend the right to dissent."
I don't really know what to think about the poster. It's interesting, definitely, also because there was no mention of the name of the organisation (or person) who put the posters up. I was concious of a feeling of surprise though: the only politically inclined posters I've seen before have been advertisements of some election candidate or political party. I've never seen posters with a message beyond "Vote for me".