any point going to Giant Sequoias NP in the end of March?

Hi, as I have read, many roads get closed in the winter, will I manage to get to any part where I could see giant sequoias at this time of the year?

The park is open at that time of year, and a popular winter sports area. Both Sequoia and Kings Canyon will have snow into May. I suggest you rent a 4X4 SUV or truck and you'll be fine - don't know how many big trees you'll be seeing? google for US National Park Service website, and click on the entires for those 2 parks - they are back to back in the Southern Sierra Nevada range, California/Nevada border.