The problem with the OIDs not getting added from the mibs was because the MIB file name and the MIBdefinition were different. The dependent MIBs may not be there in the mibs folder.
Solution: The module name and file name should be same to ensure that the SNMP parser can find the dependent MIB. The first MIB may have a dependency on second MIB. The Mib parser will not parse all MIBs in the directory due to performance reasons. It will look for a file with the exact name as the module name of the parent Mib. Hence it is required to have the module name and Mib file name the same to allow the Mib parser to find the dependent Mib. For proper parsing of a mib file, the mib file name and the mib file definition should be of same name and case. Check if this is the case and change accordingly.
If you have a vendor MIB that you can load it in Applications Manager. You can either upload MIB from Admin Tab-->Upload/Files Binaries or You can copy the MIB to ..AppManagerHome\working\mibs folder.
Any MIB file should be named as follows:
Open the MIB file in a text editor and copy the name exactly as it appears in the first occurrence of following line.
JUNIPER-MIB DEFINITIONS ::= BEGIN
Here the name of the MIB file should be JUNIPER-MIB without any extensions.
JUNIPER-MIB.mib or JUNIPER-MIB.txt are not correct name
Below the definition line look for the IMPORTS from other MIBs and upload the dependent MIBs as well. The dependent MIBs should also be named appropriately according to its definition name.
Now add the device you want to monitor from New Monitor-->SNMP/Network device monitor
To add attributes go to the monitor details page-->Click on Add attributes-->Link-->Select the appropriate MIB from drop down and select the required attributes for monitoring.