Nifty refers to the Nifty 50 Index, which tracks the performance of 50 of the most liquid stocks listed on India's National Stock Exchange (NSE). The Nifty is one of India's most watched stock market indices and is commonly used as a proxy for the entire Indian stock market. The index value is based on the total market value of all the stocks in the index relative to a specific base period. It is computed using a free-float market capitalization-weighted methodology.

The nifty 50 index fund is an investment vehicle that aims to replicate the performance of the Nifty 50 index. It is a type of index fund that holds all the stocks in the Nifty 50 index in the same proportion as they are represented in the index. The fund's value will fluctuate based on the performance of the companies represented in the index. The Nifty 50 index fund is considered a low-cost, diversified, and passive investment option for Indian investors. It can be traded like any other stock and held in a Demat account.

Here is a list of the current companies that make up the Nifty 50 index as of my knowledge cut-off date:

1. Adani Ports and Special Economic Zone Limited
2. Asian Paints Limited
3. Axis Bank Limited
4. Bajaj Auto Limited
5. Bharat Petroleum Corporation Limited
6. Bharti Airtel Limited
7. Bajaj Finance Limited
8. Bajaj Finserv Limited
9. Bharat Heavy Electricals Limited
10. Cipla Limited
11. Coal India Limited
12. Dr. Reddy's Laboratories Limited
13. Eicher Motors Limited
14. GAIL (India) Limited
15. Grasim Industries Limited
16. HDFC Bank Limited
17. Hero MotoCorp Limited
18. Housing Development Finance Corporation Limited
19. ICICI Bank Limited
20. IndusInd Bank Limited
21. Infosys Limited
22. ITC Limited
23. Kotak Mahindra Bank Limited
24. Larsen & Toubro Limited
25. Lupin Limited
26. Mahindra & Mahindra Limited
27. Maruti Suzuki India Limited
28. NTPC Limited
29. Oil & Natural Gas Corporation Limited
30. ONGC Videsh Limited
31. Power Grid Corporation of India Limited
32. Reliance Industries Limited
33. State Bank of India
34. Sun Pharmaceutical Industries Limited
35. Tata Consultancy Services Limited
36. Tata Motors Limited
37. Tata Steel Limited
38. Tata Power Company Limited
39. Tech Mahindra Limited
40. TATA ELXSI Limited
41. UPL Limited
42. Vedanta Limited
43. Wipro Limited
44. Yes Bank Limited
45. Zee Entertainment Enterprises Limited
46. Bharat Electronics Limited
47. Bharat Forge Limited
48. Canara Bank
49. Indian Oil Corporation Limited
50. National Aluminium Company Limited

It's worth noting that the composition of the Nifty 50 index may change over time, and it's essential to check the current design of the index before investing in a Nifty 50 index fund. Additionally, conducting thorough research and seeking professional advice before making investment decisions is essential.