Cruise, en route

Mumbai Control Calling, Unable to Comply, Cross at Lower FL

5 turns, word for word from the oral. Read the pilot lines out loud.

The exchange

5 turns in order
01
You, the pilot

Mumbai Control IFLY 160 go ahead

02
ATC

IFLY 160 Mumbai Control, arrange flight to cross 80 DME BBB at FL 330 or above

03
You, the pilot

Unable to cross 80 DME at FL 330 or above due to aircraft heavy, will be able to cross at FL 290

04
ATC

IFLY 160 Mumbai Control, climb FL 290 and maintain due to reciprocal traffic at FL 300, report 80 DME BBB

05
You, the pilot

Recleared to FL 290, will report reaching and 80 DME BBB