Hi Binu,
MNTCNT can also be maintained within the customizing menu (SPRO > Integration with Other SAP Components > Customer Relationship Managment > Basic Functions > Data Exchange Conditions). Transaction SM30 and using the customizing button leads to the same menu.
To my knowledge this table is used to control the maintenance of condition records for the combination "condition table, condition type". If you customize a conditon type in ERP and want to create/maintain condition records in CRM then you have to insert an entry in table MNTCNT.
For that you can check also the IMG activity documentation of the above mentioned customizing menu.
For the transfer of condition records from ERP to CRM with only displaying purposes within CRM, table MNTCNT is not necessary.
Best regards
Christoph