Dear Swati, there are various books available on Indian Labour Law, apart from S.P. Jain and N.D. Kapoor. The best book, according to my knowledge, is mentioned below:
1. Industrial Relations and Labour Laws By S.C. Srivastava, Publisher: Vikas Publication
2. Industrial Relations, Trade Union & Labour Legislation By P.R.N. Sinha, Publisher: Pearson Education, New Delhi
3. Labour Law By Taxmann, Publisher: Pioneer Book House
4. Personnel & Labour Relations: An Evolutionary Approach By Nash, Allen, and Miner J.B., Publisher: Macmillan & Co
5. Industrial & Labour Law By B.D. Singh
Thanks & Best Regards,
Vikas Ranjan