1). Make a backup copy of your tea/x.x/bin/tea.tra file.
2). Open tea/x.x/bin/tea.tra file and add -Djava.io.tmpdir="<path to new temp dir>" at the end of tibco.env.TEA_START_PARAMS.
Example : tibco.env.TEA_START_PARAMS=-Dtea.conf="%TEA_CONFIG_HOME%/conf" -Dtea.data="%TEA_CONFIG_HOME%/data" -Dtea.logs="%TEA_CONFIG_HOME%/logs" -Djava.io.tmpdir="/home/tibco/teaTemp"