How to get placed in Core Companies

Can you please guide me how to get placed in Core Companies??????

There are a number of core companies present in India which recruit a number of candidates by their own way. Companies usually conduct an entrance exam

Eligibility criteria:
-You must have good technical and communicative knowledge.
-You must not have any backlog pending.
-You must be graduate from recognized university under particular stream with a minimum of 55-60% marks.

Selection procedure:
Written entrance exam
Technical exam
Interview
Other selective rounds which may be different for different companies

Exam pattern:
Aptitude
Reasoning
Technical question
General English questions

Partial list of Core Companies:
Accel Frontline
Accenture
Aditi
Adobe
ADP
3i Infotech
AAI
ABACUS
ABB
Agreeya
Apps Associates
Aricent
Ashok Leyland
Aspire
Atos Origin
Axes
Bajaj
Bank of Maharashtra
BEL
Akamai
Alcatel Lucent
Allfon
Alumnus
Amazon
Amdocs
AMI
Andhra Bank
AppLabs
BEML
BHEL
Caterpillar
CDAC
CGI
Changepond
Ciena
Cisco
Citicorp
CMC
Consagous
BirlaSoft
Blue Dart
Blue Star
BOB
BPCL
BPL
Brakes
BSNL
C-DOT
Cadence
Calsoft
Canara Bank
Canarys
Capgemini
Caritor
Convergys
CORDYS
Crompton
CSC
CTS
Cummins
Dell
Deloitte
Delphi-TVS
DeShaw
Deutsche
Dotcom
DRDO
Genpact
Geodesic
Geometric
Globaledge
GlobalLogic
EDS
EIL
ELGI
ELICO
ERICSSON
Essar
Fidelity
Flextronics
Freescale
FXLabs
GAIL
GE
Godrej
Infosys
Infotech
Intec
Integra
MindTree
HP
Google
Grapecity
HAL
HCL
Hexaware
Honeywell
Indian Airforce
Indian Airlines
HPCL
HSBC
Huawei
Hughes
IBM
IBS
ICICI
iGate
Impetus
iNautix
Miraclesoft
Mistral
Motorola
Mphasis
MTNL
NIC
Nokia Siemens
Kenexa
L & T
Intergraph
IOCL
iSOFT
ISRO
Ittiam
JSW
Keane
MECON
Microsoft
L & T Infotech
LG Soft
Lifetree
LionBridge
Mahindra Satyam
Mastek
Maveric
McAfee

Do Girls can place in core companies after completing electronics and instrumentation engineering?what are the technical skills needed?what are the instrumentation companies in chennai?kindly reply