ORGANIC IS all about concepts
Inorganic is Rattalization
Physical is mathemtical and involves concepts
Almost all the chem is about concepts
If you are clear in concepts, go for it
Otherwise donot even think about it


if u hold BSC with Chemistry, yo shud once check books n notes and evaluate that how much rapidly you can go through scanning your notes n books .........u will be in a better position keeping in view CSS-Past papers as well
Dont let chemistry get onto you........just attack it with the deepness of your concepts, polite techniques and logical thinking......its the key
BS Bahl organic will take time if u r starting now.......although it is very good book and well suggested by above fellow....its a sincere suggestion i must say.......u shud also see K M Ibne Rasa BSc Organic Chemistry
and agree with Zafar Iqbal Inorganic Chemistry and Ilmi Physical ITS OK for CSS