House Republicans, who staged a walkout Wednesday over the seating of Democrat Frank McCloskey as Indiana's 8th Congressional District representative, returned to their seats yesterday but continued parliamentary stall tactics to show their displeasure with the Democratic majority.

However, tempers seemed to have cooled somewhat and the disruptions were milder than they had been during the last two weeks when the Democrats at times were forced to adjourn the House in frustration.

Yesterday, the House Republicans allowed debate to begin on the fiscal 1986 State Department authorization bill, which had been pulled from the floor five times in the last two weeks because of the partisan crossfire on the floor.

Enactment of the bill was requested by the Reagan administration. Republican lawmakers said yesterday that once the Indiana seating dispute was settled they had no intention of jeopardizing the administration's legislative agenda.

In addition, their floor tactics are likely to occur less frequently from now on, in order "to keep the other side guessing," one GOP official said.

"It's not business as usual," the official said. "When the Democrats get everyone to stay in town expecting a vote that's when we're not going to have votes."

The Republicans began a war of words and over parliamentary maneuvers against the Democrats two weeks ago, after a House task force with a Democratic majority ruled that McCloskey, the incumbent, had won the Indiana congressional race last November by four votes over Republican Richard D. McIntyre.

Republicans charged that the Democrats rigged the task force and that the panel had not counted all the votes it should have in order to be certain McCloskey won. They demanded a new election.

For many Republicans the Indiana dispute became a symbol of the their frustrations with Democratic domination of the House.

Democrats said that the recount was done by the nonpartisan General Accounting Office and that it was fair. They said the GOP would not have agreed to a new election if McIntyre had won by four votes.