Eligibility criteria to get placed in core companies

I want to know the Eligibility criteria to get placed in core companies; can you tell me the same?????????????

The common Eligibility criteria to get placed in core companies is that the applicant should have 70% aggregate in through out the studies, but this criteria is vary from the company to company.

For your reference here I am giving you the list of top Core Companies in India for Engineers:

BEL
BHEL
Bioxcel
Coal India
Escorts
Essar
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Godrej & Boyce
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Hughes Systique
IOCL
John Deere
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L&T Construction
Mahindra & Mahindra
NTPC
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ONGC
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Panacea
Punj Lloyd
Reliance
SAIL
Siemens