It is difficult to start mercantile law from scratch but with hard work one can do any thing.
For mercantile law you to learn
1) Contract Act
2) Sales and goods Act
3) Company law
4) Negotiable instrument Act
5) partnership Act
6) Arbitration Act

to learn it quickly buy assignments of these acts and ordinance from shop where law books are available. And for study cases buy mercantile law of Indian writer.
Stay blessed

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