Trick to Remember Maharatna PSU 's of INDIA

Trick to Remember  Maharatna PSU 's of INDIA:

Maharatna PSU of India:

Trick: GIC's Bachelor SON

Meaning for the above trick is 

1.  G- GAIL
2.  I- IOCL 
3. C- CIL 
4. Bachelor- BHEL
5.  S- SAIL(21.05.2010) 
6. O- ONGC(21.05.2010) 
7. N- NTPC(21.05.2010)