As per your request I am providing you percentage criteria of different PSU’s.

Minimum Eligibility:
You should have B.E. /B.Tech. /B.Sc. in Engg. Degree required
If you are a final-year students, the final result of 8th semester and mark-sheets must be presented at the time of interview.
minimum required number varies for different PSUs companies generally,60%-70% for general and 50%-60% for the SC/ST/OBC/PH.
PSUs allow for two years gap.
Only candidates between 21 to 30 years are selected.
Three years of relaxation is offered to OBC.
No more than 5 years relaxation is granted to SC/ST.
It is important to appear for GATE exam before applying.

Some high profiled PSUs are:

HAL (Hindustan Aeronautics Limited) needs minimum 65% marks for General/ OBC and minimum of 55% Marks for SC/ST

HPCL(Hindustan Petroleum Corporation Limited) needs minimum 60% marks for General/ OBC and minimum of 50% Marks for SC/ST

NTPC(National Thermal Power Corporation ) needs minimum 60% marks for General/ OBC and minimum of 50% Marks for SC/ST

BHEL (Bharat Heavy Electricals Limited) needs minimum 60% marks in aggregate.

DRDO (Defence Research and Development Organization)

BSNL- JTO (Bharat Sanchar Nigam Ltd.- Junior Telecom. Officers)

PSU Percentage Criteria

ORGANIZATION
BHEL
Streams applicable: ME, EE, EC, CE
Percentage criteria:
Gen- 65
OBC-65
ST/SC-60
PH-60

ONGC
Percentage criteria:
Streams applicable ME, EE, Petroleum, IN, CH, Environment Engg
Gen 65
OBC 65
ST/SC 60
PH 60

NTPC
Streams applicable:
EE, EC, Instrumentation & Control, Power Systems & High Voltage, Power Electronics, Power Plant Engg, ME, Production, Industrial Engg, Production & Industrial Engg, Thermal, Mechanical & Automation, Electronics & Power
Gen 65
OBC 65
ST/SC 55
PH 55

SAIL
Streams applicable: EC ,ME,EE,CS,IN, CH, Metallurgy,
Ceramics
Gen 65
OBC 65
ST/SC 50
PH 50

IOCL
Streams applicable; CH(Including Petrochemicals engg),CE, EE, Instrumentation Engg (Including Electronics & Instrumentation engg, EC, Telecomm �unication engg),ME, Manufacturing, Industrial engg
Gen 65
OBC 65
ST/SC 55
PH 55

ISRO
Streams applicable: ME, EE, EC, CS
Gen 65
OBC 65
ST/SC 65
PH 65

HAL
Streams applicable ME, Production, Industrial, EC, EE, IN, CS
Gen 65
OBC 60
ST/SC 60
PH 60

NALCO
Streams applicable ME,EE, C&I, CS, IT, Mining, Chemical, Civil, Metallurgy
Gen 65
OBC 65
ST/SC 55
PH 55

GAIL
Streams applicable ME, P&I, Production, Mechanical & Automobile, EE, Electrical & Electronics, IN, Instrumentation & Control, EC, Electronics & Instrumentation, Electrical & Instrumentation, Chemical, Petrochemical, Civil, E&T, Telecommunication.
Gen 65
OBC 65
ST/SC 60
PH 60

DRDO
Streams applicable EC, ME, CS,CH,EE
Gen 60
OBC 60
ST/SC 55
PH 55

DMRC
Streams applicable ME, EE, EC,CE
Gen 60
OBC 60
ST/SC 55
PH 55

GAIL
Streams applicable ME, IN, CH
Gen 60
OBC 60
ST/SC 60
PH 60

BPCL
Streams applicable ME, EE, EC, CS
Gen 60
OBC 60
ST/SC 55
PH 55

MTNL
Streams applicable EC,IT,CS,EE
Gen 60
OBC 60
ST/SC 55
PH 55

HPCL
Streams applicable CE, CH, EE, IN, ME, EC
Gen 60
OBC 60
ST/SC 50
PH 50

BEL
Streams applicable EE, ME, EC,CS, CH, CE, Telecommunication
Gen 60
OBC 60
ST/SC Pass
PH Pass

BARC
Streams applicable CH, ME, Metallurgy, CS, EC, Instrumentation & Control Engg
Gen 60
OBC 60
ST/SC 60
PH 55

Indian Railways
Streams applicable CE, CH, ME, EE, EC, CS or M.sc in Chemistry or Applied Chemistry. Metallurgy
Gen 60
OBC 60
ST/SC 55
PH 55

ECIL
Streams applicable EC, EE, E&I,CS, CE,ME
Gen 60
OBC 60
ST/SC 50
PH 50