Dear Prasannakumar,

Some general propositions for snail control:

Baits: metaldehyde, iron phosphate, beer trap

Barriers: Bordeux mixture

Natural enemies: toads, ducks, hedgehogs, carabide beetles, snakes, the nematode, Phasmarhabditis hermaphrodita,

Cultural control: Good hygiene, removal of weeds and refuges can reduce snail population.

Cultivation of the ground can kill snails and provides a not preferable habitat for

survivors. It is important to decrease the soil humidity and so the favourable circumstances for snails.

Handpicking

Here you are some resources:

http://archive.agric.wa.gov.au/objtwr/imported_assets/content/pw/ins/pp/hort/gn_control_pest_snails_slugs.pdf

http://www.gardenforumhorticulture.co.uk/pestwatch/slugs-snails.htm

https://www.greenharvest.com.au/PestControlOrganic/Information/SlugAndSnailControl.html

https://www.rhs.org.uk/advice/profile?pid=231

Thank u very much Sir!!!

we use iron phosphate (1%) here in Canada on farmer's field. Also avoid planting in shady areas and provide proper drainage. 

For home gardens and small vegetable gardens beer traps are effective. 

The best  technique would be luring technique. As the snails attracts to rotten plant materials (preferably vegetable wastes) need to place on a gunny bag soaked in water in four to five places in field. Collect all the attracted snails and bury them in a pit containing salt.