Will I face any problem for job in HCL with a backlog and s64% in B.Tech CSE????

No, you will not undergo problem for getting job in HCL with a backlog and s64% in B.Tech CSE, provided you have cleared your backlog.

Basically the HCL requires following qualification:
The applicant should have minimum of s64% of marks in graduation in any stream and have score a minimum of 60% of marks in 10th and 12th or diploma should not have any backlog at the time of application.

Following skills are also required:
C
C++
JAVA
.NET etc
Good communication skills
Good will power
General knowledge
General awareness
Knowledge in
Aptitude
Reasoning
Mathematics and have good fluency in English