As you have asked this question under the 'English' section, I assume your favorite subject is English. I would suggest doing a play in Biology though, you could pretend to be animals and plants and present the skit on deforestation or something like that. On English, maybe you can go for a skit having excerpts from classics of literature. Or maybe, you could do mini dramas on different authors' life. Best of luck. Hope I helped.
according to my interest, i would do a skit in english. there are many wonderful skits of shakespeare and there many other prominent dramatists too.if u want to do a skit based on a hollow society then u can opt for villa for sale by sacha guitry and besides that there are many other interesting subjects too. if u want to do a skit about a historical event the u can choose social.and there are many other important devotional sits in tamil language also.