Hi Binod,
you can configure the java heap size in PI exchange profile. change the max heap size (to 1024 or check with basis)
com.sap.aii.ib.client.jnlp.j2se.maxheapsize = 1024m
refer the below wiki question 19
QA for PI - One stop for all (Part - 1) - Netweaver Technology - SCN Wiki
regards,
Harish