Namaste
Organic is not a problem : just be sure to use a non-chemical fertrilizer ...check with your local garden supply :: here is for you ::
these people have a great website ...there is a list of nurseries in India in the upper right hand section...just click it on and there are new listings as well as older ones in order by area
FLOWERS OF INDIA
http://www.flowersofindia.net/
* surely there will be some nursery near you in Chennai that will be of help
* pots are ideal for Chennai with your water problem ... so I wish you the best of luck
and this looks good ::
DELHI SEEDS
http://www.delhiseeds.com/
* click on the line for vegetable seeds
ALSO
You may grow in pots things from your kitchen :: do not be afraid to plant the seeds closely together ... that is what it would be in nature :: just be sure to give each one adequate space to grow to full size
** coriander seeds for the greens
** garlic for the little sprouts for salad etc
** ginger root which makes a very pretty pot while growing
** mint :: take cuttings from mint from the store, root them in a glass of water but first remove some of the bottom leaves so they do not rot in the water :: plant them when there is a set of bushy white roots, keep the pot in partial sunlight :: they like to be a little cooler than things that grow in full sunlight ...and do not let them dry out
** methi (fenugreek leaves)
**
and you could grow radishes, get the seeds in Chennai ... they mature in about two weeks, you can crowd them ( space them about 2.5 cm apart) into a single pot, and will make a crunchy side snack with dish of sev with some slices of cucumber