NEW DELHI:<\/strong> Former President Pranab Mukherjee<\/a> on Monday underwent a brain surgery at the Army\u2019s Research and Referral (R&R) hospital for removal of a clot, sources said.<\/p>\n Mukherjee, who was unwell,\u00a0was hospitalised on the advice of the doctors and had tested positive for COVID-19 <\/a>prior to the surgery.<\/p>\n \u201cFormer President Pranab Mukherjee underwent a successful brain surgery for removal of a clot at the Army\u2019s R&R hospital,\u201d sources told PTI.<\/p>\n \u201cHe is critical and is on ventilator support,\u201d the sources also said.<\/p>\n Mukherjee, 84, said in a tweet in the morning, \u201cOn a visit to the hospital for a separate procedure, I have tested positive for COVID19 today.\u201d<\/p>\n \u201cI request the people who came in contact with me in the last week, to please self isolate and get tested for COVID-19,\u201d Mukherjee, who was the president from 2012 to 2017, said.<\/p>\n Defence Minister Rajnath Singh <\/a>visited the R&R Hospital and enquired about the former president\u2019s health. Singh was at the hospital for around 20 minutes.\u00a0<\/p>\n West Bengal Chief Minister and Trinamool Congress supremo Mamata Banerjee<\/a> said, \u201cConcerned to hear about Former President Pranab Mukherjee Da testing positive for Covid-19. My prayers are with him and his family during this time and I wish him a speedy recovery.\u201d<\/p>\n After a long political career in which he held several top posts including that of Finance and Defence Minister, Mukherjee became President in 2012 and served till 2017.<\/p>\n![\"The](\"https:\/\/cdn.siasat.com\/wp-content\/themes\/sahifa\/images\/googlenews.svg\")