Scan the content of documents before uploading in C#

if (fileContent != null && fileContent.ContentLength > 0)
                {
                    var supportedTypes = new[] { "txt", "doc", "docx", "pdf", "xls", "xlsx" };
                    var fileExt = System.IO.Path.GetExtension(file).Substring(1);  //datatime.now.tostring(yyyymmdd)

                    if (!CheckFileName(fileContent.FileName))
                    {
                        ErrorMessage = "File Name format Is InValid, Please Change the File Name ";
                        return Json(ErrorMessage);
                    }                                           

                    else if (!supportedTypes.Contains(fileExt))
                    {
                        ErrorMessage = "File Extension Is InValid - Only Upload WORD/PDF/EXCEL/TXT File";
                        return Json(ErrorMessage);

                    }
                    else if (Request.Files.Count == 0)
                    {
                        ErrorMessage = "Please select the file to upload";
                        return Json(ErrorMessage);
                    }
                    else
                    {
                        var Inputfile = Request.Files[0];
                        var basepath = fMPortalSettings.FMPortalApplicationConfiguration.HelpDocumentPath;

                        if (Inputfile != null && Inputfile.ContentLength > 0)
                        {
                            var filename = Path.GetFileName(Inputfile.FileName);
                            var path = basepath + filename;

                            Inputfile.SaveAs(path);
                            objFMHelpModel.CreatedDate = DateTime.Now;
                            objFMHelpModel.Link = data.Link;
                            objFMHelpModel.Description = data.Description;
                            objFMHelpModel.FileName = fileContent.FileName;
                            objFMHelpModel.ID = data.ID;
                            helpService.AddorEditHelpDetails(objFMHelpModel);
                            ErrorMessage = "File Uploaded Successfully";
                        }
                    }
                }
                else
                {
                    ErrorMessage = "File Does not contain any Data";
                }