Lapse of a bill

Sir my doubt is When A bill passed by the Lok Sabha and loksabha dissolved, but pending in the Rajya Sabha,it will be lapsed but why can’t it will be passed in rajya sabha,as it is permanent house

Party in power may or may not have enough strength in upper house because the same depends on parties in power of state governments.

Governments usually initiate the process from lower house where they have enough majority to push the bill.

Now imagine what happens if it is done from the end of upper house ? Most probably bill get stucked there itself.

Governments at the end of their term usually starts from rajya sabha end and preserve the bill even after the dissolution of loksabha. For this to happen, leaders of party in power make efforts to convince opposition party leaders.